steadicams are just better than glidecams; glidecams are a knock off basically. but i have a glidecam hd 4000 which i use for my T2i (i bought the 4000 instead of the 2000 so i could use it with my HVX too) and I love it. Takes some practice, but it's great once you figure it out. Unless you're doing professional films, I don't really see the need for a glidecam.
and I would say get the 11-16mm, because they're both tokinas, so its not like the 17-40 is better glass than the 18-135 (i don't think).