UC3 Controller (can't find one)

You don't want that. You have a Mystic LED and a Quad Gem LED.

You'll either need two of these(the manuals states the UC3 is compatible with both) or better yet: a DMX controller, such as the DMX 192 or DMX Operator.

My recommendation: a DMX Controller. See where you think lighting may grow in 5 years and buy a controller that will allow you to grow your lighting rig without outgrowing the controller and not going insane on the pricing for a controller.

Get a DMX Operator. You'll thank me later but you'll curse me first becuase of what you spend on it. It's honestly not that expensive and is a really good value for the money. Thing ahead, think business.

Or, go MyDMX for a PC-based solution. Works good too.