What checkout software should I use? Please Help!

[Mukieluk]

New to this board and want to thank you all for the help in advance. I am building a site for this client and I am stuck on one of their requests. They are selling phone cards. The customer will log on put their credit card information in and then select how many mintues they want. It will charge their credit card and then update the mintues ont their calling card. How would I be able to do this or what software will I need? Once again thanks for the help.

--Mukieluk