Good point, considering the capabilities. If you do everything with EC2, you should stick with it. Otherwise, if your developer box is Linux, you are probably able to admin a dedicated Linux server (for the build environment) as well, no?

On the other hand, it makes sense to develop Cloud skills at some stage as well, and you might want to screw it up with the test&build server first, before setting up the production server ;) Probably depends as well then on how much time you have?