Thanks very much Razor for your insight. I have actually sent some fillers to Japan about the car. I am just trying to see whether I could find such car in Australia and NZ as I know there are many which are raced over there.
FYI, I did think of a 3 litre bottom GTR or a GTS running a RB26. But that would propel my team into the Open Group, where anything goes and where the really really big boys are! These are teams with pro drivers and big budget running GT3 Cups/Murciellago R-GT and the likes! This year, there was even a Murciellago R-GT prepparing for Le Mans running in the race! The car was so damned fast that everytime it lapped me, I did not even see it in my rear view mirror!!!

But they failed to finis as they retired after 7 hours in the infamous Malaysian sauna!
My team is in group A, which is production car (FIA Articles 254/255/256/261/277) where mods are allowed in accordance with the regs but obviously the original engine block must remain as it is (may be bored up to 0.5mm). Body weight may be reduced but body parts cannot be changed with anything other than the original material (except for window and rear glass). The car's silhoutte can't be changed as well. The competetive cars in Group A are the Hondas/Lotus ( we were neck to neck with them until we retired!).
But of course, I aspire to drive a super duper GTR in Group O one day. I think a properly set up GTR within reasonable budget can give the GT3 Cups and others a good run for their money!!!