Yes, it's a good charger, in my experience, it seems to terminate correctly every time and just works well.
The TK70:
Check out the official website with dimensions etc
and this excellent HKJ review
and the main TK70 thread.
In my personal experience with it, it's a fantastic light. Brightest flashlight I own, and works superbly on NiMH. I don't recommend using Alkalines, but you've already said you're getting NiMH cells for it, so no worries there.
I think the strap on the TK70 is a bit of a let down, but other than that I'm happy with it.
RE: D cells:
Any quality brand NiMH cell with 8000mAh plus should work fine. Try to get LSD ones if you can, so they don't discharge when the light is sitting around.