hi there,
if you are working for any developer, you will end up signing their agreement for sub contractors, like every other trade does. therfore you will be agreeing to comply to their terms and conditions, and their terms of payment.
believe me, any terms and conditions that you submit with any quote or tender will be overridden as soon as you sign their standard sub contract agreements.
the terms and conditions are really the least of your problems, and should really be lower doen on the list of thingd to do.
so good luck
regards
martin