The Jaguar Drivers' Club XJ Register

Hi Members
I am hoping to purchase a Jaguar XJ X300 series 1996-7 in the near future. Please can anyone give me advice on which model, size of engine or year is the best one to sort, also of any problems that i should look for before exchanging any money. I'm looking to spend around £2500 for my first Jag. Look forward to reading your comments Robert.