Use Git.
Git is a great tool that allows a very flexible workflow. It has lots of benefits over subversion/cvs, the biggest of which is the ability to branch and merge seamlessly. This can't be overstated. The merge-hell that ensues when attempting to use svn's branching and merging is a thing of the past. For a better case on why to use git, check out http://whygitisbetterthanx.com/
Use Hudson.
Hudson is the easily the best CI tool in the game. The reason Hudson is the best is that its easy to configure (for one or multiple nodes), it has a ton of plugins, and handles the 90% use case extremely well. You are in the 90% use case. People like Mozilla aren't. Check out C. Titus Brown's talk at Pycon for more info. http://pycon.blip.tv/file/3259794/ (If you decide that Hudson isn't what you should use, check out buildbot)
Use Webfaction (or Rackspace Cloud).
Webfaction is a great starter ground. If your needs are low, check them out. Beyond that, I'd suggest taking a hard look at Rackspace Cloud (RSC). RSC makes scaling out much easier and their pricing model is very palatable for things that aren't bandwidth intensive (ie: most things that don't require tons of uploads/downloads). It starts at $10/mo. Their management console is good (save the DNS administration interface, but even that is more than bearable). If your needs expand beyond RSC (doubtful), you would do well to check out Amazon's EC2. Companies like RightScale can help when it comes to scaling out.