Yeah, Amos,
I've been thinking for some time about using an external mic.

I think I could rig up rig up one of the mics I already have to use for direct input. I'd just have to use the right kind of adapters.   
Sometimes having a mic cord lying across the floor and propped up near the performer can pose logistical problems that don't exist when you just have a dig. camera or laptop sitting a few feet or yards away. But I'll look into that mic you suggested.