a k series swap is about 10000 dollars depending on how much u get the swap for. on average they go fro about 7000 to 12000 with mounts, k pro, axles, swap and all. sh*ts mad paper. my fully built b20vtec swap was around 12000 said and done. but to the op if ur gonna be boosting there really isnt a need to do b20vtec theres more of a torque gain for all motor. boosting ur gaining crazy torque on any b series motor u use but if u wanna be different i guess. ide say either b16 or b18c would be more reliable boosting. and put about the same numbers.