> I suspect I'm going to have to do copper on poles to make it viable, but how do I find out who owns the poles and what they charge?

That's where a lot of leg work comes in. You'll have to start asking the city who owns them. I started by emailing the first person who sounded like they had the title of "secretary". It took about 5 emails getting batted around before I found out.

> Also I don't have any idea how to go about purchasing upstream bandwidth - any advice there?

Again, this is the leg work on your part. Do all the research you can and figure out who has fiber running nearby. You're going to have to tap into that for service. If it's the provider you go with who owns it then you won't have a seperate dark fiber leasing cost. CenturyLink, AT&T, XO, TW Telecom, Layer3, Qwest (many of these have merged together, but they sometimes use older names when referring to circuits -- so a qwest circuit might be running nearby but you'd go through centurylink to get it) will all be more than happy to take your money, but most of the backbone providers probably won't return your phone calls if you're not talking about 100G connections.