So far I've found the Art DJ Phono Pre II on the budget end that gives these options (100pF & 200pF). Then there's the Pro-Ject Phono Box II SE, the Tube version, and then the Jolida A9. Or you can get something like the TCC-750 if you want 220pF or the original Pro-Ject Phono Box for 100pF if you don't want it switchable.
And I don't quite understand how a 125pF from headshell to cable end on the Technics 1200 means that particular cartridge would be optimal for it. It depends on the cart. Put the cartridge's inductance in that worksheet on the left, the 125pF plus the phono's own loading (e.g. 125+220=345) in the middle spot, and hit the button. It will tell you where the peak is and then scroll down to find out how far off from the 47k ohms you are. Try a different value for the phono's loading (50,100,120,220,340,440, etc) and see if you can get closer to 47k ohms.
Right? Tell me if I'm wrong.
Also, as far as I can tell the only cartridges that seem to need something other than 47k ohms are the ones with inductances of 50 mH, like the Grado Prestige. On those, you'd be better off with like 100pF and 10k ohms on the phono pre end, correct? But then I'm wondering if Grado really voiced all their carts just with their own preamp. I would assume they didn't do anything like what we're talking about.