I tried two of the 1010VS-141 parts in series to get about 300 nH (we have a nice sample kit) but they also got real hot at well below my target pulse rate. Again, skin effect apparently wrecks the current capability. If I change the PCB, I could maybe use four or six of them, and maybe cool them from below with gap-pads to my baseplate.
Putting these air-core resistors over my PCB ground plane is another interesting complication. The mag fields may be heating the board. Gotta investigate that.
I still don't know if some core material might help. I've requested some powder toroids from Micro-metals, and I guess I'll buy an assortment of ferrite-core inductors from Mouser.
Nobody seems to publish current-vs-frequency specs for their inductors.
Maybe a milliohm-range axial-lead vitreous-enameled power resistor would have the right inductance, but that would be hard to find. I could let that just get hot.
Fortunately, my customer is slow getting his gear together, and we can demo at a low pulse rate and hand-wave about the next spin.