Let me preface this by saying that I'm no expert with this stuff, but I have some experience. Also, I've been at this employer for a couple months now, so I don't know where all the bodies are buried just yet.
Where I work has a widely distributed network. There is an ASA5510, but from there it goes over cat5e, or fiber, or dark fiber, or wireless bridge, or carrier pigeon...whatever was the "in" thing at the time of expansion into that building. So, there are 6+ buildings, and each has a unique setup, with whatever random switch - some cicso, some linksys, and I know I saw a dlink kicking around.
The point of all of this: The guest wireless isn't restricted at all. I'd like to lock it down a bit to isolate it from the internal network, and do some bandwidth restrictions if possible. Instinctively, I thought about setting up a vlan with acls...but I fear that vlans wouldn't be compatible across the entire network, so there would inevitably be a place where that wouldn't work. Are there other options?
Also, I'd be interested in buying new access points. There are some old Cisco 1100s right now.