What do you need? List!
1. Find reliable programmer.
2. Find reliable hacker.
3. Find access point to POS network & info about this POS environment.
4. Find the 0day vulnerabilities source which will provide you them few days before they go to public (you will never find the hacker who will find them by himself, believe me).
5. Find $XX,XXX.00 to cover expenses for 0day vulnerabilities & buy them.
6. Your reliable programmer should write an exploit using this vulnerability.
7. Your hacker should hack the POS & get permanent access to it w/o being noticed there.
8. Your reliable programmer with your reliable hacker collaboration should find the way to make memory dumps from environment and convert them to plain/text & which will have connection to your servers & will send you what they saved from memory by your request.
9. Find reliable seller.
10. Invest in advertisement.
12. Find the way to wash your money.
13. FIND THE WAY to stay free.
14. Profit.
What will stop you on this way? List!
1. Budget is too high for start. You can not even imagine

2. There are too many steps which should be passed for success.
3. Mistake at anyone of them will bring you back on half of year - few years in progress (depends on which step you got problems, better not at 13

)
Your first tries (regarding to your post ALL & ever) will be failed definitely.