I'd say good luck in getting them to sign anything but "their" standard
boiler plate crap.   If they will sign an agreement for you, build in an
interest rate effective so many days after an invoice is presented to them &
have lang. that says the contract is considered to be based in and will be
enforceable under the laws of  your state.   That way the balls in you
court in collection actions not theirs.

The problem is there are just to _amn many out there who will work for
peanuts and not give a rip about anyone else,  then belly ache when the
$$ are not paid.