I'd go for hitachi meself , i have a massive old 110volt hammer drill and its taken dogs abuse for years and its fine, 9" and 4.5" grinders same thing , a set of brushes went on the small one thats all.
The problem is with all these makes is the quality doesn't seem to remain constant, what can be a great make now can be rubbish in a few years.
Panasonic.. 3.3 amp hrs. You could almost spin a diesel crank with the torque they have. great for site work, better chucks than Makita, indestructable.
Panasonic EY6432GQKW 15.6-Volt 3.3Ah NiMH 1/2-Inch Cordless Drill/Driver Kit : This model features the longest running 3.3 Amp Ni-Mh batteries in the industry, compared to other 18 Volt tools. The drill/driver weighs only 4.8 pounds but delivers 390 in./lbs. of torque.