Bush Hog 2208 series for one. Here is another from Woods. I am sure there are others and all of them are pricey..
Woods' rugged and powerful DSO8.50 Offset Dual-spindle is ideal for orchards, tree-lined fields and any setting with overhangs.
woodsequipment.com
Dan
Damn ... that Woods is pretty slick. The hydraulic gauge wheel height adjust is cool, but the offset is awesome.
@eichhoma, perhaps you could use the Woods for inspiration for hydraulic gauge wheels. As
@hedgerow mentioned, you could convert an existing rotary cutter for as little as a couple of hundred dollars or a lot more depending on whether or not you have wheels, hubs, axles and such laying around.
I have a rolling chassis trailer frame with two axles (3,500 lb each) that I got for free. I had to tear down the old camper body and take a bunch of crap to the dump to get to that stage, but I could remove one of the axles and use it for my rear blade after some modification. An appropriately sized hydraulic cylinder and two hoses along with some steel and some welding would get it done. A turnkey system is hard to find, and very expensive, so making something up would undoubtedly save a lot of money and perhaps the same is true for you. The image below from the Buhler/Farm King owner's manual shows a turnbuckle to adjust blade height, but replacing it with an hydraulic cylinder would be the way to go.
@JasonW used the term "semi-mount" since you don't need a top link connected to raise the rear of the implement when you have adjustable gauge wheels. However, in order for the offset ability to be retained, in the example below you'd need to have a top link. The same must be true for the Woods cutter that
@TheOldHokie linked to. In order to swing the cutter left or right, the gauge wheels need to be off the ground (ideally) so a top link is still required.