This one went through a long and torturous build process over almost two years. All I can say is don't believe the "advice" you find on talk_ass. However, in the end, it turned out to be a pretty nice instrument.
I have several hand drills, cordless and corded. For real work, a massive DeWalt cordless powers easily through concrete. But you don't need all that to build a guitar, in fact, you don't even want it. The DeWalt is expensive and weighs a ton. For light use, a little cordless Ryobi or Black&Decker will do just fine and is a lot lighter on the arm and the wallet.