I would preferably go with a B16a2 or B18C1 or C5 but if you want to stay with the frankenstein theme, go B20/VTEC. I like the B20/Vtec a whole lot better than the LS/VTEC because of the better low end torque is better and the B20 crank is able to withstand a little more high end RPM. Also the B20 bottom end has a low compression for excellent turbo options.

I have two friends one with the LS/VTEC turbo with nitrous and the other with a B20/VTEC turbo. The turbo setups are identical. The only difference is the tuning and the ECUs. The B20/VTEC walks away after 120mph from the LS/VTEC turbo. Both of these setups are in 92 Integ LS and RS. Just make sure that do the Frankenstein correctly using the right parts and not lowballing on stuff.

The H22 is to me not even close to worth it because I've seen tremendously cheaper swaps make better 1/4 mile times than a gutted H22 in a 93 CX hatchback. The swap is complicated and doesn't produce amazing grace like a GSR swap does.

Just my .02