the cheapest way is to just have a toggle for vtec
hehe..next would be the rpm activated switch...
both these pages have some good info..not only for the vtec controller, but for the swap in general. remember, you'll need a relay in addition to the switch...
http://www.geocities.com/crx288/d16z6swap.html
http://www.angelfire.com/ca/DrOhm/hybrid.html