When pellet stoves first came out I was running the National Wood Energy Association and wrote about several of them in our Association publications. They are incredibly efficient and very clean burning. The problem then and now is whether or not they are cost effective.
The units themselves are quite pricy and pellets have never caught on enough that they became a cheaper form of energy. Despite recent natural gas price hikes, its hard to justify an alternative to gas on cost alone.
On the other hand, if savings is not as important as the look and feel of a wood stove, a pellet stove is a great device. Keep in mind that you wont see a roaring fire or the beauty of flames licking off a few logs. Instead it features a small combustion chamber with a limited view.
In comparing models or brands, I strongly suggest you go to a shop where you can see them operating.
Good luck with your shopping and I hope you will enjoy your wood energy project.