a nice driveable rb30e would imo be nicer than an animal of a rb25det
the rb30 has decent amount of torque, and a lot more power and torque is realesed when head work is done
start of basic, extractors, exhuat, intake, 95octane fuel and advance timing just a shmidge
after youve done and are getting bored with this level, pull the head off, get a bit of porting and polishing done to it (maybe even a 3 angle grind), decent cam (wade make a good cam), cam gear and you should have a fun, torque, decent power rb30e
ps b4 the second stage, i recommend a r31 silhouette LSD (4 pinion if possible)
either that or a spare centre that has had a few sticks of weld put into it