> "So I'm tempted to encrypt the credit card info and store it in my database in case I want to switch in future."

Seriously....just don't. The world of pain you'll be in if you mishandle this data and the symmetric encryption key will probably see you or your clients made bankrupt.

Please read up on PCI-DSS before even considering this:

https://www.pcisecuritystandards.org/document_library