The proper model nr. is "Ultragain Mic 2000" if that's what you mean. It is a very solid no frills box unlike never B-stuff. There's only a gain control, a variable low cut, and phantom power. Its successor the Ultragain 2200 offers parametric EQ, a tube & stuff at about 1/3 of the price. So I guess they must have made compromises somewhere. Among the visible ones is that the 2200 comes in a much lighter, thinner housing.
Lots of mic preamps are very similar to the Ultragain schematic. You already pointed out the Project 66 preamp and the ADA8000. Zillions of mixers sport similar preamps as well. So there's nothing original about it. Still the Ultragain 2000 sounds better than most. I suspect it has in part to do with the 2SB737 transistors.
re impedance: what mic manufacturers usually quote is the recommended minimum impedance. But it's true (at least in my experience) that many mics sound good with impedances slighly above 1k. Still the Ultragain 2000 is very compatible. I've yet to find a mic that doesn't like it at all. So I personally don't see a reason to change the input impedance. I've recently gotten one of those cheap t.Bone ribbons (which sounds nice btw), and my slightly modded Ultragain is the mic pre it likes most so far. I tried an ART preamp with variable impedance (not my own), but it really didn't like the ribbon at any setting. But I think it's mainly the way they implemented the impedance control, not the low impedance itself. Maybe it wouldn't be a bad idea to design a dedicated ribbon preamp or add an additional input especially for ribbons (lower impedance, no phantom power).
