I'll throw my 2 cents in just for kicks. With any grill, go heavy or go home. Yep the more it weighs the better, hold heat better, last longer, and yes you can smoke on it. It will costs some coin up front, but it will be worth it.
I have a flame broil grill that is probably 5 years old now I guess. Cast iron burners, cast iron cooking grates, home made steel burner tents, helps keep flare ups down. It will grill from 200 degrees up to 500 depending on settings. Weber's are definitely good, just stay away from the couple hundred dollar cheapo's.
For your situation you may even want to look for a dual side burner model, If you want to spend the coin you can get grills, where you can use the gas or burn charcoal, some have smoker boxes built in with their own small burner, Just a matter of how much you want to spend. If it is going to sit outside much, look at models where there is alot of stainless used in the exterior construction. I get monthly news from here, Smoking-Meat.com
Lots of great ideas, and links to tons of sites too. BTW yes I have a charcoal grill too, and smoker and whole hog cooker. Though I don't use the grill much, the gas is just too convenient, and whatever you do if you get cast grates DO NOT clean them, treat them like a good old cast fry pan.