Good luck with the photo gig Michael - I hope it works out for you.
Another thing you will have to contend with is reflections of yourself/clothing and other objects in the glass of the art being photographed. We are doing this right now at a local arts archives, setting up procedures for our interns. Wear dark clothing as lighter fabric may show in the framed glass. You may also want to consider putting a black backdrop behind you. This will eliminate hard reflections. Our observant photographer also taped out the white camera name and wrapped the metal tripod legs in black cloth.
We decided not to go with electronic flashes due to simplicity, but instead are using daylight balanced fluorescent bulbs in our reflectors with a custom white balance. And with artwork, you want the WB to be as accurate as possible.