Hi Don, I will start replying to your last sentence first. I might disappoint you, but usually, the cheap will not be good. Obviously, we all have various definitions of 'good', but...as my father said "I am not rich enough to buy cheap". At the same time, the most expensive doesn't guarantee quality.
If you look at the beginning of this thread, I posted the tools I am using, one of the rotary tools (the first one from the bottom) similar to what you may need. I Don't find a good use for it, but this is my own experience. It does have a keyless chuck, but it doesn't have variable speed control. Also, it is luck a good torque, but I think all cordless don't.