simon
best bet is to join as many zooki clubs as poss and search for some one who is up grading their susspension set up this will work out much cheaper for you also think about gettin some spring lift rubbers these are another fairly cheap way of gaining more height you can usually get these of eblag,
tyre sizes are a funny thing wot sort of brand are you thinking about getting?
colways, grizzlys, teknics, bfg,
and again are you going to stick with the 15" or move to 16"GV rims? as some makes of 16" tire are cheaper than the 15" version
let us no how you get on
simon