I would probably go with a B18C1 swap. It won't have the same torque as any B20 setup (less displacement) but the GS-R engine has a lot of punch for a lightweight Honda. The extra power on the top end will really help you when you hit the straights too (as opposed to a LS or B20). It will also probably be the easiest install, no head swapping, no tranny swapping and if you shop around, you can get a complete swap ready to go in with everything you need. It will be expensive though, most complete B18C1 swaps go for $3300 or more. You can sometimes find them cheaper, but you get what you pay for and sometimes you end up missing little items like shift linkage, a nessicary mount or and ECU which can add up quickly and give you a lot more downtime if you don't know you needed it before you pulled the old engine.

Another option you might consider is just a straight B20 swap (no VTEC head). You can find the long blocks for around $1000, that gives you a pretty big budget to find a tranny, axle's, shift linkage, mounts and ECU you'll probably need. Swapping on a new transmition really isn't hard. If you can do an oil change or brake pads, you can swap trannies (it's only about 15 bolts off than on if the engine's out). You could do a B20 long block, B16A tranny and intake manifold, and an LS (or even DX civic) ECU for well less than $3000 and if you want the extra top end power, swap on a VTEC head later (along with upgrading the block itself). Of course, you could always do a B18C1 swap now and have the block re-sleeved to 2.0L and get to the same place (but with the GS-R's better oiling and coolant system stock). Seeya.