I teach in a very tough school, and my kids know more about evil than I care to consider.
On rainy days, they use my classroom for inside recess and watch videos. I have seen the hardest boys enjoy some very and lovely videos:
"Max and Ruby"
I love Veggie Tales as well -- pick one, any one, they're just wonderful!
These shows are all slower-paced, gentle, family-centered, and funny. The kids just absolutely love them -- perhaps because my hardest kids see a way of life that makes more sense to them than the insanity they have to deal with at home :(
Be willing to slow the pace. Don't give in to the idea that boys must have action-packed, fast-paced, good-guy-bad-guy stories. It sounds like these boys have had more than their fair share of action and fast-paced living. Unless you've been experienced it yourself, it's hard to imagine the survival habits developed by kids who have to be ready for anything at any time.
Children who have lived in a constant state of uncertainty need some down time, some time to think and react more slowly -- think of it as a chance to re-wire the brain to be able to deal with consistency and predictability. Introduce them to innocence and gentleness. Watch the shows with them and talk about the silliness and the sweetness. Laugh at the silly moments and say "oh no" when the characters get into those innocent goofy messes. Basically, you're teaching them safe and appropriate reactions.
If you have cable/satellite in your home, check out Nick Jr. It's a great station with not questionable thing I've ever seen. I only just cancelled my satellite, and my son is seven and a half, but that station was still his favorite!
God bless you for serving God's little ones. He will give you the grace you need to do right by them.