Trying to power a 100-watt Cree Xpe array as efficiently as possible with dimming
This is not a place to look for specific LED driver models. That said, in general terms:

1) Do not buy anything else from that buyer. Anybody who advertises a 22 volt, 3 amp LED as 100 watts is untrustworthy (as in, liar). For instance, they claim that your module is compatible with their 100 watt driver. Nope, so sorry. Minimum voltage for their drivers is 30 volts, much higher than your module accepts.

2) I've tried to do the math using the published data sheet (pdf from http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Discrete-Directional/XLamp-XPE) and I cannot see for the life of me how they get their numbers. 6 blue LEDs will, in fact, drop a nominal 21 volts at 1 amp. The reds, however, just don't work out. 

So, since I'm not sure how the individual LEDs are hooked up, I'd have to recommend using a dimmable 50 watt LED driver. Any more and I'd look for damage somewhere.

Also, I'm not sure if you're aware of it, but your module MUST be mounted on a fairly thick metal plate, preferably aluminum, if you want anywhere near maximum power. If you don't do this, you will overheat the LEDs.