You don't say where you are, but its likely there's a Real Estate Investment Association somewhere near you. Try
our list. Find one, go to it, and talk to other members. Someone will likely be able to point you in the right direction for forms.
You want local forms. Here in CO, there are some very specific laws about foreclosures, for example, using the wrong form can land you in "font size jail". I'd sure hate to tell my cell mate I'm in for using the wrong font on a contract, but that's the way the law reads.
No, I've not done a wholesale transaction. I'm focused on REOs, at the moment. I am on the buyers list for a number of local wholesalers, though, and have spoken with quite a number of them. Its a fairly common topic at our REIA, so I've heard fairly thorough descriptions of various forms of wholesale transactions.
I'd recommend getting a few books on RE investing, and start reading. "Flipping Properties" that you mention above, for example, walks through the process.