Is it just trouble finding a 250k version? That style seems to be fairly common, and the size doesn't seem to be unusual, but the stuff on digikey seems to hit at 100k and 500k and not in between. I'm certain the manufacturers would make other values, but they may not sell enough of them to keep a stock, so it may be a special order.
If you can't find the right termination style, you could always bend right angle pins or trim down solder lugs to fit, or even run wires from them with them facing away from the board, since it gets all its mechanical strength from the mounting nut, having it mount directly in the PCB is sort of secondary.