Just put an RB20 in the GTR for daily duties and use the honda for the track! Sorry...
On a serious note. Just do a cheaper rebuilt (without stroker - 400kw - $$$) and just keep it going. If you upgrade to 400kW's you'll need 7k brakes, 5k suspension, 2k tyres etc to use it. Depends on how far you want to go. I think of Gareths (roudyr32) GTR with his 200 and something kw's doing 1:52's at PI on street tyres.
To me a car to have on the track is better than a car sitting in the garage to someday hit the track again.
Track time in any car = FUN!