Hi Emily, I like the option that Beau suggested. Here is one that I like:
http://www.ebay.com/itm/15mm-Rod-Support-Dovetail-Quick-Release-Base-plate-fr-Rail-DSLR-Rig-Follow-Focus-/271366879743?pt=LH_DefaultDomain_0&hash=item3f2eb9f9ff
It's half the cost of the Zacuto and has adjustable height Rods and a Quick Release Plate. It is going to put the center of gravity of the camera relatively high which could be an issue when balancing but I think it will work fine.