We have our site up and running very succesfully. This is a small project to change our current payment processor from Worldpay to Paypal.
Clients purchase from us using our custom registration, we want their payment to be actioned by paypal rather than the current worldpay option, then the callback script updates their records on our site. (The call back script currently works with worldpay).
I know this is a sensitive and simple job so need someone with great feedback and great rates.