The thing to remember with the battery operated power tool is cheap prices are just that.. cheap. The batteries do not last and you really get frustrated when you are up there working and the thing stops after just a short time. Also look for one with high volt batteries. 18 volt is a good start. Although I have an old 9 volt Makita drill that is still running after being dropped off roofs, and left in the sub zero cold.

I use Makita and Black & Decker Professional grade. Personally, I hate the battery operated tools and have been going to pneumatic tools lately. Thise pneumatic air nailers are the bomb!! While the hose is a PITA, the recovery time is fast and clean. Some of the better ones out there are Milwaukee Brand, Black & Decker Professional Series, Makita (but they have really went downhill the last few years), DeWalt is another good one.

For only a few cuts, any of them will do. Just get something with good power. That and a good sharp blade and the cuts should come nice and fast.