Hostgator Reseller Vs MediaTemple Dedicated-virtual

I have several small websites that I currently host with HostGator without any issues (although I wish customer service was better).

The websites are very small and currently don't require any significant disk space or bandwidth requirements (we currently have less than 10.000 visitors every month).

The problem I currently have is that these websites were all set up in different accounts which are a pain to manage and probably more expensive than required.

We plan to grow both in number of websites and bandwidth capacity requirements in the near future.

I have come to two options: Stay with Hostgator and get a reseller account( http://www.hostgator.com/resellers<dot>shtml ), or switch to MediaTemple and get a dedicated-virtual account ( http://www.mediatemple<dot>net/webhosting/dv/ ) (I have heard good things about MediaTemple).

Can you guys suggest which option would be better? Or a different one? Below are the characteristics I'm looking at.

Price - As long as it’s within market standards according to service I don't mind paying more for a better service. It is important that payment is easy from outside the US. Customer service - fast, effective, available 24x7. Ease of use / reseller - Easy to maintain several independent websites in a single plan. A plus if they have a good reseller setup.

Long term company stability and management - I wouldn’t like the company to disappear or be inconsistent in its business practices. I would like to avoid making changes in hosting provider.
Scalability - We shoot to grow and develop additional businesses that require more capacity. Don't want to change later of host provider when this happens.

Security - Known reliability of external attacks and good backup model Known reliability running the latest version of Drupal and Expression Engine.