Fantastic news! I'm really glad you'll be handling the stands for this. I know the 3 I already have from you are the centerpiece of my collection.
I know I'll regret saying this, but if you really knock it out of the park (which is why I know I'll regret saying this, because you always do), money wouldn't be an object for me. That said, I'd say a comfortable price ceiling would probably be $200 given the original cost of these sabers. Personally, I don't have a ceiling (within reason), but it's tough to add too much on top of $1500 and electronics and an install, so I'm trying to think about the group as a whole here.
Personally, I feel full custom is the way to go, which incurs big price, but I don't believe the stand needs to have a huge footprint. I'd say no more than 4" longer than the saber itself. The saber needs to be the center of attention without dominating the entire space around it with a huge stand. The things I would like to see are that it would be easy to remove and place in the stand (remove is bigger than place), some kind of a unique position or holding solution for the saber, lots of gold and silver mirrored acrylic (along with the proper amounts of black to balance it out), and if you can work with wood, maybe a thin wooden base that has a dark stain.