go with the LS/VTEC so i can say mine is faster then urs. lol

i wouldnt go wit B16 cuz the stroke is too short.

the B20 has a weeker block compared to the LS. if u do go B20 go wit the B20Z, which is 99-01 i believe (has higher comperssion pistons)

GSR everyone has a GSR be different.

ITR im not sure about.

i still say go wit the LS, it has a good bore and has a longer strokwe the the B16. but it's all up to u.