hey mate hows it going, im currently doing an rb25det conversion, can be found in memebers project forum, awesome setup but if you wanna do it properly its definately gonna start adding up... i have spent about 28k so far on parts alone, without suspension, diff, rims n tyres, oh plus interior(seats, gauges ect) haha oh plus paint. yes its definately not cheap but with that i will have a pretty solid car! will end up around i spose the 40k mark... dam im stupid to spend that at 18 on an apprentice wage but hey live and learn
definately go rb25, dont even consider 20, waste of time imo... for the extra 1000 or so when you look at it 39000 or 40000... 1000 isnt that big of a deal and you will be thankful you have an extra half a litre
anyways im prob just goin on by now so all i say is best of luck hope you have a car your happy with which ever way you go
Jason