Some random thoughts:
Three main things people want in a tripod - stable, light, and inexpensive. If you choose well, you can get two of them, if you choose poorly, you get only one; you can't get all three.
Consider buying legs and head separately.
Carbon fiber costs more, is lighter and damps vibration better. Also better in the cold.
Look for heads with clamps that are compatible with the Arca-Swill system (closest to a universal system there is). That's especially true for landscapes, L-bracket, pano gear, etc. The plates are what you attach to your camera and collared lenses, they go in the clamp on the ballhead.
Spend more now or spend more later… http://www.bythom.com/support.htm
The best legs are Really Right Stuff and Gitzo. The best heads are Really Right Stuff, Kirk, Markins, Acratech and Arca-Swiss. Avoid heads from Gitzo.
Manfrotto legs are a good compromise between quality and value. Their heads, less so because of their proprietary clamps.
$100-200 for a tripod and head is cheap - if it's sturdy it will be heavy.
I've heard good things about Sirui and Feisol. Also, the Oben tripods/heads from B&H jsut got some good reviews at the-digital-picture.com.