you are a type whatever comes to mind person aren't you?
what model crx do you have?
the low down:
zc is cheaper to buy and install (all d series do not require mounts)...zc is also misleading b/c there were several different flavors (dohc, sohc, sohc-vtec)
the b16a is more powerful and has more potential...it costs more and requires mounts and some minor wiring...it has the biggest aftermarket for any sport compact engine