Which do you need, a cordless drill or impact driver? Of course you need both, at least I do. If you've never tried an impact driver take the time to do so, and time to stand in the checkout line once you decide to buy it.
DeWalt's New Cordless Power Tools and Re-envisioned Hand Tools
DEWALT DC500 2-Gallon 12-to-18-Volt Cordless/Corded Wet/Dry Vacuum - Offering convenient corded and cordless cleanup, the two-gallon DEWALT DC500 wet/dry vacuum sucks up big work shop messes and job site debris quickly and efficiently. A high-efficiency wet/dry filter... - Power Tools - Tools & Hardware - $99.00