Although I have not used them yet, I highly recommend Hondata. They are the go to guys for anything related to tuning hondas. They also have fixes for a few of the common issues with the new gen si's. Mainly being the hanging throttle issue.
I am planning on getting the hondata reflash installed....but one main concern is.. willl it be ok with just my Cold air intake with it? b/c everytning else besides my CAI is stock...
you can use one of there maps that they have tuned for those parts. it wont be the maximum gains but it will be really close. the rsx TB wont work because its throttle by cable. you can go with the tsx one which bolts right on.