Hi, I would like you to look at www.siteshosting.com.
I can offer you all of the features you are looking for. How ever we can not offer you a customizable control panel. How many accounts will you be hosting in the $50/month fee? I can give you 1 Gig of space, 20GB/month bandwidth, 10 IP's which will cost $15/month, Namservers which will cost $12/month, accounts will be setup in less than 10 hours.
Setup Fee: $15
Monthly: $60/month and able to host 10 accounts. I know it is $10/month more that you did not wish to pay for.
We also have a plan that cost $118/month. You will be able to host 70 accounts, online control panel to add accounts, unlimited features to offer your customers. We have 2 clients using this plan and they love it. It's just like having a server but you will setup accounts through a browser. If you have any questions email firstname.lastname@example.org. Thank you