I sold my parts car for 1000 bucks, and im looking to spend some money on my car.. I have a 93 integra with 240xxx K/M on it. Now the stock b18 runs strong, but I'm not too sure a motor with that many kms can handle boost.. So I was playing with the idea of a B20b swap with boost, and I was a bit concerned on how that motor will handle boost.. What would you guys suggest? Here are some options I am considering:

B18 LS/VTEC - Using my existing bottom end with a b16 or b18c vtec head.
B18 - Put some minor work on the head, and run 8-10 psi boost.
B20 - Either boost or vtec, not sure yet. I heard that there are piston to valve clearance issues.. Plus the b20 has weak cylinder sleeves, which is a concern for boost.

I can get a turbo for cheap and piping will all be custom. Just dont know enough to make up my mind . Any help will be great. Thanks guys!!