k&n typhoon intake and the CFM ORP are awesome easy bolt on's to get 10-15 more whp. if you ask me there is still quite a few extra horses to be squeezed before going to fi of nitrous. another somewhat simpler option would be adjustable cam gears to advance the timing a bit. possibly a bit more aggressive cams (although the SVT's are pretty good as is). i'm not a fan of underdrive pulleys because i like my music real loud but that's just me.
...although ya gotta love a boosted SVT! wish i had the know-how and budget to boost mine :/