I like to use dr lava's Groove 2. I believe it's only $14. The hard part is the wait once you order it. It looks like laser surplus parts has it in stock.
You can also buils a ddl driver. Some of the guys here have also gotten repurposed led drivers to work with modifications (steviedezie did, I believe)
DR Lava New Grooves over Heat So fast Now and then start Blinking On me. I dont know what it is. I had it set to 420mA running off 2x 10440 cells Heatsinked. After about 30 seconds it would start blinking. Then If i shut it off and turn it back on i will only get ~15 seconds before it starts blinking.