dedicated servers are the best, but too expensive.
try getting a vds to start, there are some good offers at fdcservers.net
i like the unmetered bandwidth their servers offer.
Best option would be get a Dedicated server with a new host as you're not gonna be able to run a bunch of fast proxies with close to 100% uptime on VPS for a long time.
I presume other people have already suggested this. However, I recommend getting a dedicated server, it's the best option, especially for proxies as they are excessively on the resource side of things. A VPS, I don't think so, especially for multiple proxies.