I have to agree with alot of the stuff thats been said here,
Ive had a Land Rover defender 110 Hi Cap Pick up, They cost a fair bit to run plus you have the maintance and the toys you decide to get for it, had a Jimny as well, it was a pig on the road with a set of muds on it and a 2.5" suspension lift, cant fault it off road in anyway other than getting stuck in the deep ruts left from bigger trucks plus i had fueling issues which i couldnt afford to sort out so had to sell, Ive also had an SJ for off roading only, it was a good laugh manual choke was a pain but you kinda get used to them, Never driven 1 on the road so cant comment on that but the leaf springs were sore off road,
Dont get me wrong i love 4x4s and im planning on doing something really stupid like saving for a Discovery, but if it was me at your age i would buy a diesel motor and get some years behind you,
But on the other hand if you have the cash the time and willing to learn buy a 4x4, join some of the off road forums and see what they say. But i think insurance will be a killer for the next few years, im 23 had my licence for 4 years and im stilling paying stupid money.