Server Hosting Recommendations?

[Tanmarro]

Hello,
I have a forum website(invision board) and need some inputs to select a dedicated server.
My forum has 8 million posts (Including posts and topics) in total.
Right now i am using Xeon 5260 2 bay chaisis, 12 gb ram, 400 gb SD
I just want to know how can we determine the server configuration ..based on what factors?
Current issues i am facing is database table crashes....
What host is better for getting servers at: Regvps.com or GTHost.com server hosting solutions?
Any reviews please?
Thanks