I am also a high school computer teacher, and our building got renovated about three years ago. I was able to ask for lots of goodies too, but be prepared for the contractors to ignore whatever suggestions you make.
That being said, there were a few important elements I insisted on. One is that I could see all the students' screens from a central location. Mostly that meant having all the PCs facing outward against three walls, with me in the middle. This was a huge improvement over the back-to-back rows we had before. The downside is that kids have to turn around if they need to see the board or the teacher.
My class is in the Career and Technical Education school, so I'm training kids to be sysadmins, programmers, and technicians. Due to the nature of the class, we have a central rack with networking equipment that's easy for the kids to crowd around. If this is something you need, make sure there's plenty of space on all sides, and use a cable tray to bring in the wiring. Also, I asked for power to be dropped from the ceiling to the center of the room so we could setup work benches to troubleshoot hardware. (That's one of the things they neglected to give me.)
Natural light is a wonderful thing, but I wouldn't worry too much about glare as long as you don't have shiny glass screens. If students will be sitting in front of these things for an hour or more at a stretch, good (and large) LCD displays will reduce eye strain. Similarly, don't expect kids to sit in crappy chairs for long periods of time. But don't get swivel rolling chairs; they'll just race and spin in them.
Probably the most used piece of technology in my room is the projector. I'd definitely get a decent one and install it where everyone can see it. I also like to be mobile in my lab, so I've got an iPad to walk around with and take notes on student work.
As long as you've got space to spare, give students as much elbow room as possible. High school kids need a little personal space so they don't get on each others' nerves. Also, more space per PC makes it easier for students to work in small groups, as they can gather three or four people around one PC.
I've got some software I'm partial to, as well. It's nice having something like Faronics Insight in the lab, which allows me to monitor what everyone is looking at, limit Internet access, or share my screen with everyone. I'm not tied to that particular brand (thought it's what I'm using right now, and works on PCs and Macs), but rather any software system that has those functions.
My lab is due to be upgraded in a year or two. I might go with laptops if it's in the budget, but we've got to work out accountability (for theft), upgradability, and a few other issues. I certainly wish I had one or two for myself, though.
I hope this helps some.