Most reputable affiliate programs will provide weekly direct-deposits -- if you earn enough commissions. How "instant" do you need payments?
Here is another thread with this same question as someone on that thread pointed out, it would be too risky for them to pay affiliates right away... new ones, at least. ClickBank is generous by offering the option of getting paid once a week. I don't think it gets any better than that, at least for large affiliate networks.
I never heard of an affiliate program that pays right when the sale is made. That would be an operational nightmare, not to mention they would be taking on way too much of a risk. Most programs pay on net 30 to new affiliate, some even later than that. You'll need to establish a history with an affiliate network before they switch you to net 15 or net 7. That's just the way the game is played.