i can't see how can u rev a rb25 or even rb26 to 10k without opening the motor
more like 7k of rb25 and 8.5k for rb26
and the stock 10:1 and 8.5:1 compression will only give u around 200hp, that's at flywheel
either of them u will need a highly balanced, blue printed bottomend for the high rev, with custom forged pistion to bring the compression up.
u will also need some cams to make sure the engine will make power up to the built redline
plus hd valve spring + more
even with such a motor, i still doubt it can pull low 200rwkw
might need to throw in some giggling gas too to reach yr aim