G201,G202, G203, G210 and G212 are the stepper drives from Gecko.
The 201,202,203 are fixed at 10 microsteps the 210,212 have full, half 5 and 10.
Best bet for you I would think would be to stick to the 201,202,203. Probably actually 201 or 202 would be ones I would go for.
Hood