I would agree with some on PayPal (on certain products, preferably low cost). However, with higher end products and depending on the price of the security deposit I would suggest a higher end solution. Yourpay.com and Authorize.net are usually the two I suggest.

Sure Paypal has become a little better in the past couple of years but I feel alot of people still feel negative towards them. Plus I am a little old fashioned and believe that if people see a high end gateway (authorize.net) they will feel a little better giving out credit card numbers. That is why I usually put their logo on the form page.

DO NOT forget the SSL!! I still see that alot as well....lol