since you're 2001 then you need an obd2b-obd1 conversion harness...get it from www.boomslang.us they are they best quality and one of the least expensive. chipped p28. i have tuned 1000's of honda/acuras and i have plenty of gsr maps that'll work for your setup as you have it.

you can get some gains out of it w/ just a cai, but you will get even more gains out of it w/ ihe than just having the cai. you could get away w/ waiting to tune it until after you go ihe.

also, it sounds like you want to get the job done on a budget...i wouldn't suggest spending the extra $ at this moment on hondata. you can get the job done just as well w/ a chipped p28 running crome.

feel free to give me a call if you have any questions. 678-614-3596.