I dont know alot about the MR16, but if it puts out 12v DC, and want to use flex type leds, then you need what i call "DUMB" led strings, they are 4 wire, 1 common and 1 for each color - Red, Green Blue leds. So it will take 3 channels on your controller to run a string of these.
You might be better off using the cheap $7 DMX controllers out there do you dont have to use so many of your channels for each string.
Try looking at holidaycoro.com and David's LED and DMX controller offerings to get a better Idea.
The strings listed in the wiki will ONLY work with smart string controllers...
If you need more info - just hollar....
Myk