I would get the 1100mah nimh packs (the ones for $21.99) as nimh is a superior battery technology, and one advantage is that the memory effect that used to plague the old nicads is greatly reduced. So topping up isn't as much of a sin, and ensures your battery is always full of juice.
It would be nice if you could get the nimh's in a higher mah rating, 1200 would be nice, but 1100 should be fine.
-uDi