I asked Jerry direct.
You can take my 61Mpix full frame, shrink it to APS-C and downsample to your pixelnumber ;-) probably this will bring a better result than taking a 100mm tube lens and a smaller sensor.
Edit: those are the prices for forum members when contacting Jerry:
5X NA 0.15 USD255 + shipping cost
10X NA0.3 USD429 + shipping cost
20X NA0.3 USD580 + shipping cost
20X NA0.45 USD698 + shipping cost
50X NA0.45 USD799+ shipping cost
50X NA0.65 USD1099 + shipping cost