I don't think you've really thought this through at all...how is the ACA going to fund some sort of certificate and ensure their name stays good by performing visits to these LFS to see they are following the standards set forth by the certificate itself?
Furthermore what's to keep some one from not just lying and setting up a front to get the certificate, and then going back to making it a business.
The shear magnitude of regulating things for certificates, and keeping it an honorable practice, not just somthing to make more money off of, requires a lot of effort - time - and money.
Even then, what would the punishment be? Reprimanding the certificate? You can't take somthing back when a person has made payment - they would have to keep an online database of who is still qualified, which means more work, and even then how many people are actually going to check that database after seeing a certificate?
The only way for somthing like this to work - is to make it a government regulation with penalties and fines set forth by the law for misrepresentation if the certificate's authenticity is abused.
Fish stores would have to up their prices a lot more to even consider obtaining the certificate due to the cost of upkeep that would be required to make the certificate mean somthing.
This isn't really all that feasible when you look at it from a business perspective - it's not like fish store owners are in the business to get rich, this is a very hard and very trying business to make money on period, as a sole source of income.
I don't know how many places are dedicated to cichlids alone, I only go to a handful of LFS that I've been going to for almost 15 years, because I know they have a good reputation. But I do know that you can walk into almost any fish store on the planet and see your run of the mill cichlids that bring in cash, oscars, red devils, gold saums, various africans ect.