AbleCommerce Shopping Cart Software

If I wanted to change the Checkout to have a persons credit card
info displayed when they return to the store (for a quicker checkout)
can I do this without having the full source code? thanks
(I will also give the user a "save card" check box option)

The source code is not needed. One possible way is to save the card info is to put the information of card in user settings. I wrote some code to put this functionality. I have attached the customized file. Hopefully it will help you

thanks . . I'll take a look at it.