Yes, you could have your own domain. By the line of your questioning, I don't think you should be even considering a dedicated server. Also, re: the below quote...
Originally posted by blue27 With dedicated you have your own server.
With virtual you share a portion of a server but you have full server rights.
I've seen virtual accounts (shared hosting) described as "virtual server packages" so you may not have "full server rights" but we'd have to see the package to know for sure. Blue27 was talking about VPS (virtual private servers), though even with those I'm not sure you have "full server rights" exactly (too long to go into now). Moot point.
Anyhow, people get dedicated servers for many reasons. More space, customization, control, security, etc.
I think you may be more interested in Shared hosting.
In either shared or dedicated or virtual you can use your own scripts, (some scripts may not be allowed in shared) and you should have no problems with ecommerce in a shared environment.
If the ecommerce is a large scale project then a dedicated server would be the way to go.
I'm sure I can start small and update my plan as my needs grow with no problems, correct? Or should i anticipate and allow myself room for growth from the beginning. Would it be a big headache to update my hosting package with the average host?
I had a virtual server once, it ran fine performance wise, but the problem I had was when the provider was rebooting the main box, this of course forces your virtual server to reboot. Apart from that it was fine.