I don't know what the 'ACSS Certification' is, but the physical limit for each radio on max number of clients for each model of AP you posted is 255 client devices (the limit of the PHY). Now, of course it's not recommended that the AP-103 carry the same number of clients as say the 225, as the performance of 200 clients on an AP-103 would pretty much be abysmal compared to the 225. However, you CAN put 255 associated clients per radio on each (not recommended but possible).
Recommendations (which are fluid depending on use case) could be:
AP-103 = 30
AP-20x = 50
AP-21x = 75
AP-22x = 100
These are ballpark figures to use and are NOT a fixed value (you could do 25/50/75/100 or even 30/60/90/120 if you want).