There are several that make 7' mounted rigs..........and for less than $6500.
7' M.H.D. CUTTER W/2 WHEELS W/CH [MH72TC] - $3,023.00 : Howse Implement Company, Your source for tractor and farm equipment parts and supplies
Heavy Duty Rotary Cutters
And if you're not absolutely set on a twin-spindle rig there a scad of others out there that will sell you a 7' cutter for less.........Kodiak, Mohawk, Taylor-Pittsburgh, Modern Mfg, King Kutter, Big Bee, etc.
There are a lot, but I don't think any of them off hydraulic height adjust. I need that feature. Woods is the only one I can find that has hyd height adjust.