I've been setting up some Hikvision POE powered camera at my place;
Bullet
I have installed several of these, as well as some of their domes, and I have been very happy.
If you can get a cable out there, I would do POE.
You can have it up to 328' away with just a CAT5e for both power and data.
If running a new cable is an issue, and your wiring is in good shape, you could install a PowerLine adapter set...
The Ubiquiti wireless stuff is really good if you want to go wireless, but I haven't read good things about their cameras..
Check here for some more in depth information :
http://www.networkcameracritic.com
http://www.ipcamtalk.com/forum.php