the only other thing you might need would be a set of polarizing gels for your lights--they run about 50 bucks apiece for a sheet big enough to cover the output of a tota light or a strobe head. the other alternative would be a set of the old kodak polalights if you can find any. having the ability to cross polarize (lens & lights) is a big help in copywork....
btw--the bencher is bigger than an MP4 (I've used both the MP4XL and an MP3 as well, and surplused both of them also.) and the lights are better. When I used the MP4, I took the sidearms & lights off and replaced them with either speedotron strobes on stands or lowell tota lights on stands, depending on what I was working with....better coverage & more even.
in our studio, we use a Linhof copystand as well. it has a shorter column, but the build quality is superb. it's a great stand for shooting small objects--for lights we use strobes or hotlights, it just depends on what we're working on. I use a glass stage on that sometimes to shoot coins as well.