I've used the following for many years now.
http://www.vtr.org/buyers-guide/bill-of-sale.pdf
Be sure to have it notarized...You get one copy, as does the buyer.
As for the idea of not releasing the car until the title has been switched over, let's face it, now that the internet is so widespread in use for selling vehicles, this is not always a practical idea since you could be selling the car to someone out of state................
Bill S.