hi mate
welcome to the addictive world of offroading!
best bit of advice I can give you, is buy a cheap cherry for offroading & keep a normal car for everyday use!! you will soon get the modding bug & you will find it easier & probably cheaper to have a dedicated offroader! the hassle of cleaning it ready for work, fixing it when you break something after a day in the mud will soon wear off!!
xj's are really cheap at the moment, so go pick one up for about a grand & learn with it!
I know loads of folk who have modded XJ's (like in your pic), me included & they are very capable offroad. go for a 4 litre with plenty of spec like aircon, leather etc.....the 4 litres also have an auto box which to most folk i know is easier to use offroad!!
Where are you anyway? You are welcome to come have a nose around my XJ.......
Plenty of Jeepers here to talk to:
www.rockznrutz.com