Can anyone help me with the Sales Contract\Purcahse Agreement

[Kenneth Stallworth]

I have 5 different sales contracts and I don't know which one to use. In my efforts to wholesale properties and buy REOs I don't have any deals in the works yet but they all seem to be slightly different with different lengths ranging from 2 pages to 13 pages long. I know there are supposed to be a couple of clauses in the contract such as:
"And/or assigns" or "and/or nominees"
Inspection clause
Choice of escrow company
Right to extend

However except for the And/or Assigns clause I'm not sure of the exact legal language or where this stuff is supposed to go in the contract. So if I modify a sales contract what sort of language should I make sure is in there to make it legal. Should I contact a local Realtor and ask them or get lawyer
Any thoughts or suggestions.