I use
www.allabouthosting.co.uk I have a mini-reseller account with them which allows me to host as many domains as I want and allocate disk space and quotas as I see fit across all of my domains.
A budget reseller account would probably do you for the time being, and you could always move up to the next nevel should the need arise.
And do you really mean that you get 1TB of data transfer a month? That's quite impressive!