Man I wouldn't worry so much about the chest hair. Even if you have a lot of it just trim it and keep it under control, most chicks don't mind it so long as you're not sheltering endangered species in there.
As for the back, yeah that I would definitely do something about. I've tried everything from shaving to nair to waxing and then finally laser treatment.
Shaving obviously works, except that you can't do it yourself, it doesn't last for long and gives you a sandpaper feel after only a day or two.
Nair works but it smells super nasty, can burn the hell out of you if you do it wrong, and you still need someone to help you.
I tried waxing once, and that was enough for me.
Finally I went with laser hair removal, and that has been by far the easiest and most effective method. I will say that the treatments hurt like a b*tch, especially your first one, but the results are great. If you have the money for it I highly recommend it. Personally I went with American Laser Center, and I bought a deal for my back, shoulders and neck--got it for $1600 but that came with 5 treatment sessions and a two year guarantee after that. My wallet is a bit lighter but my back is as smooth as can be, I have no regrets.