Ok, thanks folks!!
We do have a finish nailer already (and the nails as a matter of fact)
We also felt the boards should be finished first so they're already painted and cut to near length. Will cut to final length when they go up.
Ok, here's question number 2...
We already have about six can lights. She's going to move them about 6-10 inches (if there is enough wire up there)
I'm guessing that each board will need to be cut out as it's installed, going around the can light verses using a hole saw afterwards, correct?
When we've put the drywall up, I cut a hole 'near' the size of the can opening and used a rasp to finalize it, making it as snug a fit as I could.
I don't have that luxury with the boards..... I DO have a router but it's a monster and wouldn't be very controllable overhead like that (I have thought about mounting it on my router table and using it to (what's the word) "free hand" the cutout instead of using a jig saw)
I'd hold and move the board on top of the table rather than try to hold & control the router (don't recall the model number but it's the big porter cable, 2 1/2 hp or maybe as much as 3 1/2... I forget and am not a big wood worker to know those specifics!)