Paypal integration

I am looking for a PHP programmer with Paypal and/or Google Checkout API skills. I need to integrate a simple php driven ecommerce website with one or preferably both of the above online payment applications. The php app is custom written by a self taught php programmer and so may need some tidying up.

The site does not retail but hires kit out and so prices of items change according to how long they are on hire for. The integration will have to include the following points.
Delivery and collection addresses.
Delivery and collection dates.
Prices (by date as above), quantities and sizes of items.
Shipping charges.
Security deposit amount.
Minimise the amount of user data input to make for a simple, quick transaction.