A bigger intercooler = a 50*F decrease in intake temp which equates more horspower. I would say the bang for the buck is in making sure you are getting all the cold fresh air you can to the SC via a cold air intake. Then make use of all the hp you already have by improving the pump efficiency> new repitched impeller. After that, maybe a Vortech SuperCharger Impeller for increased torque thru-out the powerband, then maybe a new intercooler. This is essentially a Level 2 kit for the RXP less the OPAS, Sponsons and intake grate which is only applicable to PWC's.
Wakeboard Tower, Bimini Top, Aquatic AV Stereo w/ Wired Remotes, Sony Xplod amp, 2 - 10" Subs, 6.5" Polk Audio Spkrs, Bazooka Tower Spkrs, Custom Cold Air Intake, Custom Rotax Racing Thru-Hull Exhaust, XS Power External Intercooler, Filled Rideplate Holes