Make sure whatever you get is ALL stainless. Brass burners are good, and heavy cast iron enclosures are good, but anything else, and I mean anything, ought to be proper stainless. Otherwise it will rust all to hell. Someone gave me a grill, it was a 3,000 dollar grill. They moved and the thing wouldn't fit in their new place. It has a rust problem, and it is too big to heat up properly. You want something just barely big enough for you, and something that won't rust out.
Aluminum isn't great for an enclosure, but it's better than sheetmetal. Iron is best, but very few manufacturers make the iron enclosures with the good stuff elsewhere. Well sealed stainless enclosures can work fine, but you don't want them too large, as they can't hold the heat after you open it.
Nevermind the brand so much, what you need is something that won't crap out. I like the fake Jenn Airs in Lowes for a solid stainless grill, but they are expensive. Find something that is built like a rock.
A good old charcoal weber is great, but they need to be well taken care of. Still, you will be hard pressed to find something that will cook as easily.
Above all, you want something that will really crank the heat. Don't go too big unless you go charcoal. Don't get one with large voids that lose heat.
Cheers,
Kennith