200sx all the way
altho im slightly biased as i have a s14a with full hks 2.2 engine build and gt35
rex's are to unreliable if trying to get power out of them and if you give it a good seeing to alot of times stick with the proper piston engine lol
another thing that has always put me off rx7s altho they rev high they produce low amount of torque
altho my friend has a tasty 600 bhp rex that he competes in hks drag series but gonna have a 200 chasing him down now i hope