D17A1 swap

I have 2002 civic lx I want to swap in either a B18C3 or a K20A2, Im leaning towards the B18 because they arent as hard to find as the k20, but I heard they use different mounts and are difficult swaps. How does the k20 engine compare as far as performance and aftermarket parts. And what is required to either do a B18 or K20 swap. I know i'll need a tranny and ecu but what else needs to be done.