Stu - all i would say is that if 250 is your goal, then go for it!
IMO, you'd be MUCH better off going to 200, with it being lovley and reliable, and spending more money on brakes, suspension etc.....
I've still got a lot of xr2 bits and bobs up the garage that will aloow me to make a very fun xr2 when the funds allow..... and it won't need to be silly bhp either as i've got all of the important bits to make it handle well!