You really dont have an option of making the D16Z6 as a non-button VTEC. Your best bet is getting a b16 engine and dropping it in the CRX.

try a vacuum switch and adjust it too hit around 45 or evan earlyer. the vtech dosnt kick in untill 5 so the gas milage is better and that you dont burn your tires. porsche has a system simular to vetech that hits smoothly and it runs from vacuum. so give it a try. and tell me about the zc engine. i havnt heard of it before.