If youre looking for CPA programs the best in my openion is :
PAW (Aff-link) : Poker affiliate world is very reliable imo. Never had a problem regarding payment or support. Good thing is also that you can promote diff. poker/casino sites with one account. They also have exclusive promotions.
Your option nr. 2 would be
PAS (aff-link) : Poker Affiliate Solutions, can offer you high CPA rates, Free bankroll offer for your players, rakeback for players etc. Payment has always been around 10-12 every month.
they got the best aff-support that I have seen so far. Very helpfull guys.
For CPA I would also stay away from Full tilt poker´s affiliate program. They just changed the CPA-player rules, and I hear from other webmasters that CPA-rate now are 40-70% lower than months before the new rules.