Some more options for you to consider:

The hondata flash is what many rsx owners claim to be the best mod for the money. When you purchase the hondata flash you're going to be sending your ecu, key, and immobilizer to hondata. You will also fill out a form that describes what mods you currently have. Hondata will flash your ecu to fit the current mods you have.

The ecu is going to eliminate the dip in your powerband. It will also change your vtec engagement from 5600rpm to 5200rpm (reccomended with an aftermarket intake), and your redline will be raised from 7900rpm to 8600rpm.

I don't know what you have planned for your car. But if you're planning on turbo, or nitrous then forget about the hondata flash right now. Hondata did say that they are in the process of making a hondata turbo program.

If your plans are n/a then hondata should be the last thing you purchase in my opinion.

The only other option would be if you're planning on changing your cams. Toda offers a package that comes with their toda spec a cams, toda valve springs, and a toda ECU. The ECU program uses special fuel and ignition timing maps, 9000rpm redline, modified VTEC Activation, and modified VVT camshaft timing. Because all parameters are optimized through this special ECU program, dyno tuning of the Engine Kit is not required.

hope this helps.

and if you buy the flash, go through clubrsx.com