We don't offer those kind of packages even with our unlimited packages. For example, if you order an unlimited plan from GlowHost you will see the cPanel says 10 Gigs are available. This is our first tier. 20 gig and 30 gig are the next tiers after that.
Here is a post about it:
http://forums.glowhost.com/knowledge...mits-2313.html
The type of plan you are talking about is certainly possible but that usually done on servers that are not well managed and they usually break down a lot. These caps help us so we don't have to babysit the unlimited machines so much. If someone decides to upload their 2 terabytes of MP3 at 4 in the morning and you are sleeping you have put yourself in a bad position since most hard drives are not that big and the system will likely crash when it runs out of space.
So as you roll out of bed you have to then explain to all of your customers why the server went down, then you get to let Linux try to delete 2 TB of data on a production server which may not boot, which may require an on-site tech to fiddle with it, and once you finally do have a shell, while it does this remove process, it slow things down for everyone on that server because it will drive the load up during the removal process and until it completes which could be extra hours(?) of a slow loading server after its back online.
If you want aesthetics you could probably just write a cPanel theme to show "unlimited" here and that would solve that problem but then again I am not sure branding to that level works on shared servers with cPanel.
My best suggestion is to explain it to your customers how unlimited works if they ask. We are rarely asked the question unless someone wants to upgrade which surprisingly (or not, depending on how you look at it) is not that often.