I despise the way the term "retention holster" is used. ALL holsters are retention holsters. I mean, if they didn't retain the gun, what good would they be?
The term "retention levels" was coined by Safariland and it has nothing to do with the number of actions that need to be take to remove the gun. It has everything to do with how long the gun stays in the holster while trying to be removed by someone who isn't the owner. *Rant off*
OK, I like the Safariland ALS system. It's much better than the SERPA mechanism.
The best belt for the money is the Uncle Mike's Instructor's belt. It has a kydex insert to make it stiff and costs less than $35 if you look a little.