I have just been researching WP shopping cart apps. This is a somewhat grey area, and I haven’t seen much that’s rock-solid. The most popular one, WP E-commerce, is pretty good, but I can see why it gets mixed reviews… even though it’s very popular, it seems a little buggy and kludgy. Also, to get extra functionality, they have paid modules.
http://www.instinct.co.nz/e-commerce/
Regarding your question, this app has Paypal and Google Checkout. You pay extra for a bunch of other gateways:
http://www.instinct.co.nz/e-commerce/payment-options/
For other ideas of varying quality, in plugins try a search on “ecommerce”, “e-commerce”, or “shopping”. Indeed, most only offer Paypal and possibly Google checkout.
Good luck.