The 5508-12, 5508-25, 5508-50, 5508-100, and 5508-250 models allow a total of 12, 25, 50, 100, or 250 access points to join the controller.
This is an old document. 5508 can now support up to 500 APs if you run firmware 7.X. 2504 can support up to 75 APs if you run firmware 7.4.X.
I'm looking for some recommendations on WLC 2504 and 5508 about the the following:
Best practice and recommendation is to LAG all ports so you will be able to form a link redundancy. If one link goes down, you have other link to push traffic.