Community site (lots of modules) hosting recommendation

Hello all-

We're getting ready to take a community website live with some complicated functionality in it (kind of a halfway marker between LinkedIn and Facebook for a targeted group) and I honestly can't anticipate the traffic load...we're going to be sending emails out to interested people and those are going to number in the thousands, so we're talking (hopefully) a high-traffic site.

With Performance logs (devel) turned on and no optimization in terms of CSS files or caching, we're running at an average of 28.1 MB per page, and an average of 2,414.72 milliseconds per page to load.

I can't really sacrifice the modules enabled without degrading the site functionality, and we'd actually like to expand the site's functionality in the future to additional capabilities.

Right now we're hosted on GoDaddy's Grid Hosting (https://www.godaddy.com/gdshop/hosting/grid.asp) and it's been a nightmare for the site going down with connection issues. This is an issue with the service, not performance, so we need to switch. We already have other sites with Godaddy, so we want to stick with them for simplicity's sake, unless another place just has too good a deal to pass up.

I don't have any server management experience (CPanel only, really).

Recommendations, virtual dedicated, dedicated, and service providers? How much memory do we need? What kind of processor? What should we look for in a plan? Thanks!