Passing on what I have heard - Most brushless drills are built in such a way that all the parts are integrated the housing of the drill, rather than being a drop in unit like the brushed ones. End result is, you take it out and it won't work unless you make a custom housing to hold everything in exactly the right place.

If you can find one that isn't like that then I'd reckon a hacked TZ85A with SimonK firmware would handily control one of the 22.2V Brushless drills.