NiMH batteries are pretty forgiving. Just set it to NIMH mode and for the 1700mah battery, I'd use 2amps. For the 2000mah I'd use 2.5amps. Based on your request for a middle of the road charge rate.
A good rule of thumb for just general playing around RC driving with NIMH packs is charge them between 1C and 1.5C. Which means take the capacity of the pack/1000 and then multiply by 1 or 1.5 and that's the amp rate.
The 1700mah could easily go to 2.5a and the 2000mah up to 3a.
Batteries should come off the charger warm or even hot (but not so hot that you can't hold them in your hand). Also if you want to try and get the most life out of these batteries, don't charge them immediately after using them if they are warm. Let them cool down first.