I usually recommend to get the for civil use sensible parts of the personal soldier's equipment of the own army, as it is usually the best deal one can make, if one doesn't buy 100% at a flea market.
The military equipment is made to fit well together, serves well in the own climate, and should something really break you can replace it easily.
If you cross a town you give a relatively normal image and not the impression to be a military freak, and the risk that your equipment gets stolen is also relatively low, because it is usual.
There are of course some differences in the equipment systems, and some may be a bit better than others but it is complicated and usually expensive to get a complete foreign military equipment, and often details of other stuff do not fit correctly to it.
And that means that although I have absolutely no idea what the Persian army uses currently (my last informations are about the equipment that was issued by Dareios III.), I highly recommend to scratch some money together and try to get as much as possible of the currently issued equipment of the Persian army, of course keeping my packing list above in mind.
Magazine pouches and Y-webbing are usually useless for us, unless the magazine pouches serve as well as outer pouches of the rucksack.
But if there is some kind of ladie's hand bag, called haversack or breadbag here or general purpose pouch, with shoulder strap and perhaps belt attachment that can be perhaps mounted on the rucksack, it's sensible to get one. Often pot, bottle and mug can be put in it or attached to it, and so you get the kitchen equipment and food together, what is very handy.
It's also handy on other journeys, where you leave the rucksack in the accomodation and use the breadbag as handbag with your values or smaller stuff.
But because it usually attaches to the rucksack or fits somehow else into the complete system you can carry it well if you carry the full equipment.
I also would have a look at the field uniforms. Most of us combine it with some well fitting civil clothing to demilitarize it, like another cap or pullover or fleece jacket.
Especially the army boots are interesting if you can get them new or as good as new. And the socks too.
Although the stuff usually is pretty cheap there comes in the end a surprisingly high amount of money together that wants to be invested. But usually the investment is very intelligent because the stuff is made to last as long as possible.
Nearly all currently offered civil outdoor equipment is made to break sooner or later and usually a bad deal!
With just a few exceptions civil equipment is compared to military equipment, that can be bought cheap but in good conditions, or even better brand new, always a bad investment, especially because the current civil market tends to sell lightweight equipment that is too weak for bushcraft use or even regular use in town all the year round.
The Decathlon stuff is no exception here. Solognac hunting equipment is often OK for the here asked prices, but military equipment of developed countries usually is better.
And although Iran surely has some weird characteristics, it's a developed country without any doubt. Weird characteristics other countries have too, by the way...
If you didn't serve in the army you should ask somebody who did it to inform yourself how the Persian army equipment fits together.
Usually you have a rucksack with fitting blanket or sleeping bag, the bread bag fits to the rucksack's attachment points, the pot attaches at the rucksack outside or inside or has an own pouch, the bottle fits to the mug and that attaches to rucksack, breadbag or in an own pouch to the belt.
If pouches attach to the belt, the original belt is usually the best fitting one, and sometimes the here fitting Y-webbing that holds it as some kind of non stretching braces is identic with the rucksack shoulder straps.
So you need to know where exactly is the end of the chain of perfectly fitting items.
I could for example combine the belt, pouches and Y-webbing of any army with the current German army rucksack, but with most older German rucksack models it wouldn't work.
If you get a 100% equipment of one army, issued the same time, you can be sure that all fits with everything perfectly. And that's apart from the built quality the main reason, why most of us use military equipment. Civil stuff rarely fits well to the other.
Most NATO equipment is more or less interchangeable if it was constructed approximately in the same time. That's why we can mix it here. Often they have given it just different colours.
But older equipment of different armies usually doesn't fit well together, and so it's the best to stay in the system of only one army if one is no expert, and because it's the cheapest one can get, it's usually the equipment of the own army one should buy. That simply avoids expensive troubles.
The most often made beginners fault is to buy non fitting civil equipment and to replace and replace it until it fits somehow relatively well.
People spend a fortune on it.
If they would have simply bought a used personal equipment of the own army in good conditions they would have invested ones, would have gotten a well working equipment, and it would have served them in civil use for decades or even a lifetime.
Although I don't know the Persian military equipment I am pretty convinced that it's generally the same with it. Simply because it is always like that, and I don't know any exceptions.
I have seen in civil use personal army equipment of most European armies, by the way, made in a time frame of more than 100 years. I am no studied specialist but surely everything else than a beginner.
I simply do that, also in larger groups, since approximately 45 years and have friends who sold that all.
I also own and used quite a bit of that stuff.
I could open with it a nice little military museum...