b18b is 142hp, and b18c is 170? and b18c5 is 195-200hp
b16a is high compression, higher compression engines can't handle boost as good. If your gonna go FI then i would get a b18b, they are lower compression and take well to boost. Plus, you ahve to make sure it will go into your car. You said b16, is that a 1 or 2? the 1 would take some extra work, the 2 should go in easily. However, in my opinion, its not worth the 700 extra at all.