Check out the Primary Weapon Systems website for a good muzzle device. From what I've heard its well worth the money in controling muzzle flip and better than the slant at controling muzzle flash.
As for mounting a light, I'd go with a Tapco intrafuse forend with the removable rails. The built in heat shield does really good for protecting againt barrel heat transfer to your hands and lights, beside it keeps the weight of the gun down opposed to the aluminum handgaurds from UTG like I have which are wicked heat sinks without the rail covers. But if you like the original fore-end you can always add the UTG tri-rail mount that attaches to the barrel, but like their fore-end will transfer heat since its aluminum as well. I havent had much a problem with that ruining a light so far luckily.
If you like the AR type stock you can always do what I did, get a converter and use any AR stock you like. I've got an ATI stock with adjustable cheek rest for when I need higher cheek weld with optics. I'm contemplating a heavier recoil buffer and spring for the stock since its orignally set up for the 5.56 round.