I'z gunna be biased and say go for the 5GTT. But as clj85, they have usually had a very hard life, and I must add the turbo's do seem very prone to being problematic, expecially with overheating etc...
Don't know a lot about the XR2i other then it was fast as fook in its day and a lot nowadays seem to be well looked after by their owners (and maybe somewhat easier to get ahold of a goodun as well).
I'd love to see a 5GTT at the cruises though hehe, as much as the XR2i is a sweet car and undoubtably legendary and infamous, I think the 5GTT has a slight edge over it when it comes to being special.
Either way though, I am sure either will be exciting to drive hehe!