I have been using the KD440 shears for many years. I bought my first one new many years ago and have picked up several reasonably on eBay. They cut 14 gauge mild steel easily and last forever. They are really meant for straight line cutting, but they will cut an arc. I prefer the shear by itself.
http://www.amazon.com/KETT-KD-440-14-Gauge-Power-Shear/dp/B000BPO17W I don't like kits because it is too time consuming to change from shears to a nibbler and there are are too many small parts to get lost. We have several nibblers at the shop for cutting around curves. However we avoid nibblers because they are slow and leave the nasty chips that almost have to be picked up with a magnet.
