Hosting support

I am about to develop a web portal with few thousand users with normal content types, calender and video sharing.
I am new to a large project and chose drupal 7 for it. I have worked on it for smaller websites.

I have to deveop a video gallery. some videos are free some are paid.
I am thinking of doing it 2 of the following ways

I'm having problems after moving a Drupal website to a new server. Initially, no assets were being loaded correctly as Drupal was trying to load them from an URL such as this:

http://www.my-drupal-website.com/css/...

I would like to know which is better if we are working mainly with Drupal websites (price, performance, easy to use, etc)?

Thanks!

New to drupal but am currently developing a few new web sites locally using Drupal 7 and Postgres 9.2 on Ubuntu Linux. Hopefully I will have these sites ready to be published in a few months so I need to start figuring out the hosting aspect. At least for the first year or so, traffic on both sites should be somewhat minimal (50-100 hits a day) so shared hosting environments is perfect. One site will be more informational with some user interaction while the other will be an e-commerce site.

i have payed for hosting with domain.com but when i try and upgrade my drupal site it gets errors and when i try to go back to the old version it just dosen't work (i've had this problem before and tech support helped a little but it always happens again)
is this just a problem with domain.com? does anyone use the automated drupal setups with other host?

should i just do everything manually? or get a new hosting service?
how do you guys setup your drupal sites? what host do you use?