Poundland do a good 500ml ally bottle which are ideal for carrying meths in and cheap they do them in all colours and you could always mark it so you know whats in it.
I have used the ally can from poundland for years and no problems, just don't store long term. I have blue for water, green for unleaded and purple for meths.
when I have finished a day out I decant the remainder back in the main container, the oldest is ten years old.
How big are you looking for it to be?
If you aren't fussy, almost any string PET fizzy drinks bottle (suitably labelled to avoid accidents) will do for meths. Just make sure that the stopper is a good tight fit and won't loosen accidentally in your pack, you don't want your sleeping bag to catch fire! Yes, aluminium bottles will be attacked by meths if you store it in them for a long time. Even bottles which have an internal coating will have pinholes in the coating which will allow corrosion to start. It's OK to use them for a week or two at a time though. Don't use them for other fuels unless you change the stopper for a proper fuel-resistant type. An ordinary drinks bottle stopper will absorb the fuel and swell, then the threads will be destroyed when you take the stopper out - if you can get it out... The Trangia bottles are great for meths, convenient and easy to pour, but pricey for what they have to do. The thread on the Trangia bottles which is sealed with an O-ring seal has a habit of getting very tight in my experience. Yesterday to top up for this weeks badger watching I had to put one in a vice to loosen it.Not too bothered to be honest, .5 l or 0.6 or 1l