Can you still get them?
Only occasionally on ebay.co.uk. SJS Cycles had one up, but I don't see it today. I was sorely tempted, but was "saved" by their requirement for local (UK) buyers, and the fact that it was missing the eyelets to attach front fender stays (it was an early model, a take-off with paint wear around the mounting eyelets).
On looking further, I am not entirely convinced the Mid-Loader could hold rotational sway in check. I have a horrible feeling the bags would want to swing around the fork blade, racks and all. This may be why there is now a MarkV. Still, the Mid-Loaders gave that little bit of extra ground clearance as you have found.
...[Got a set of] Ortlieb rears thrown in with the Nomad and I was trying them on the low loaders. No good. Too low on corners and kept hitting the curbs
Been there, done that! I ran rear panniers on the Low-Loader MarkVs mounted on the Miyata 1000LT in the pre-Sherpa days. It actually worked extremely well from a loading and handling standpoint (center of gravity dropped to the point where it felt like the bike could stand on its own), but it made for tough sledding when I went cross-country through mesquite bushes and sagebrush in the desert. And yes, curbs were deadly. With 700C wheels, I could just get away with it on cornering, even as deeply as I lean (I used to ride on the tread-skinwall interface back in my uni days...and still have the scars on my ribs and armpits -- ouch -- when I didn't get away with it. Skinwalls don't have as much traction as tread. You have been warned.
I love using and building racks. The set I made for the folder frame I'm brazing are the strongest I've seen, but they're also the most compact, thanks to the 20" wheels. I used tubular cro-mo tubing and milled mounting points that support the weight on the threads and heads of allen bolts; each rack easily supports my weight at 172lbs/78kg. The back rack also supports the folded bike and allows it to be rolled like a trolley or parked on itself when not ridden.
Please let me know if you find and try a Lid-Loader; I'd love to hear your user impressions.