Our department issues Peerless, but I prefer the S&W, can't point to anything factual, but I think they just "feel" better. A couple of guys have Hiatt cuffs, and they seem to be really good as well.
The new ASP cuffs have the advantage of being larger and key holes on both sides, the downside is you need a different cuff case for them, and I've seen them bind up after being compressed in a guys duty bag all summer in Texas heat. But that's probably more of a "take care of your gear and it will take care of you" than it is a statement about the handcuffs themselves.
I have a Safariland, Tex Shoemaker, and a no-name oversize cuff key, just remember whatever you buy, try it in all your cuffs first before you trust to it on the street, as sometimes different cuffs will have different key tolerances. I don't trust the ones that come with the cuffs because they usually aren't a good strong steel like the aftermarket ones you can buy.
Just about everybody makes some kind of flashlight holder, mine is just the leather loop where the head of the flashlight keeps it from falling through. Since it's just a loop and not actually a pouch, it fits my Streamlight Stinger, also Surefire G2's and a bunch of other lights.