I put up some of the cheap Lowes solar lights several years ago and they are still running. I think I changed out the batteries once. Some have died over time at various locations, but by and large they have been very reliable. When the batteries are new they will run all night and run less hours over time. The animals seem not to be bothered at all by them. Heck, I wonder if they sometimes use them as beacons.
I also made a motion detecting setup with 6 volt feeder battery and solar panel. These are very bright and will come on and work all night. I mounted them on a tall t-post. The animals don't mind these either. Here is a pic:
As for the weapon mounted lights, they work to a decent extent. As DNS said, they will get spooked the more they are hunted with them. One trick is to start out with the pointed above them and then slowly lower it down to aim at them. Some prefer red, some prefer green. I used green. I would also agree with DNS that white seems to be less accepted by the animals, but some have reported success.
Warning: This is a slippery slope. Most folks start out with a single light on their scope, but soon the addiction overcomes you and you find yourself with all sorts of night vision gear. It causes very erratic purchasing behavior and the wife will be seeking help for you.
Hope this helps.