Daniel, thanks much for the advice.
I'd love to do this on 4x5", but as is the case, I'm just going to be using my D*. Truth be told, they were going to just "take some pictures", probably with a crappy point & shoot (and straight on flash no doubt!). I stepped in and said 'let me do this'.
Unfortunately I'm not going to have the perfectly ideal gear. I'm going to be using my Panasonic GF1 (micro 4/3) and will have an adapter for my FD lenses. I wasn't able to procure a macro prime in time, so I've got to make do with what I've got. My choices are 28mm f/2.8, 50mm f/1.4 or f/1.8 and 85mm f/1.8, plus a 35mm f/2.5 (FL). If this was a big gig I would've done things differently (and earlier), but I know that for their purposes, this will be more than sufficient. Furthermore, this is part "gaining experience" and part a favor for my aunt, who is involved with said museum.
Any recommendation on which one might have the flattest field and best performance at the distance ranges I' looking at? How about the ideal aperture?
And good call on trying out my lighting; I better do that tonight, as I'm leaving tomorrow!