Add more payment options for Buy/Sell php script

I have a PHP multi-user buy/sell script (SMARTY) with Paypal payment (only). I want to add more options for payment 1- Hand to Hand 2- Wire Transfer Changes needed: Payment type should appear in (Show Item Page). Selling process begin with adding item to cart -> Checkout -> Choose Payment Type. For (Hand to Hand) and (Wire Transfer) payment, the item will be on-hold until Buyer pay the cost and seller confirms that, and later the buyer confirm delivery. New payment Methods affects (Transactions/Transactions History/Invoices/Item Stock/Item Commission/Item Sell Request/Shop Payment Policy). Payment Status (Done/Not Transferred/Suspended/Refund ). Beside any additional modification may not listed above related to payment methods All new payment methods should support multilingual. I need expert people that have previous projects in PHP shopping programming