I'd offer you ours but we're full at the moment until I decide to setup a new server..
The best thing I could offer now would be the advice to setup a few more and get your own dedicated server..
Anything else you need proxy related just ask...
I would recommend you get your own dedicated server. I got a deal on webhostingtalk.net, make sure you go with a decent company though. My server was $60 monthly (unmanaged), pentium core 2 duo, 1gb ram, 250gb hd, 2000gb bandwidth, plesk. I upgraded it to cpanel and 5 ips for $30 more. My proxy network wasnt huge, but I was able to run my sites on it..
The biggest problem are spam complaints, somehow someone was using my proxies (and server) to send spam messages. Each time someone reported a spam message, I got fined $10. Happened four times before I cancelled the server (had sold proxy network)..
Theres a guy on the proxy.org forums called thewird, I would go speak to him if I were you. He resells beefy servers for some big company (layeredtech maybe? cant remember.) All of the spam reports go directly to him, and he takes no action.
I wouldn't recommend a shared host, if you are serious about your proxy network..
My advice: Wait until September (school starts) and get a dedicated server...
I know who you're talking about and I would not reccomend going to him..
Anyone who colocates is a possible problem..
Go direct with a larger company for your dedicated..
Softlayer is the only option in my mind..
Also.. Getting spam complaints is part of having a dedicated server. It is unlikely it every had anything to do with your server but they've spoofed your IP in the emails..
You'd notice if someone was sending thousands of emails from your server...
With proxies, a dedicated box is the way to go. If you try shared, you're going to get an email from your provider about the amount of resources your proxies are chewing up. Lots of good dedicated providers out there: LiquidWeb, ThePlanet, Softlayer, etc.....
Thanks for the help guys. I've started a new thread about VPS vs Dedicated. Some feedback there would be great too!..