Long story short: One of my sites is growing like crazy... millions of pageviews a month, and I need it optimized.

I keep having to upgrade the server to accommodate the growth. I'm at the point now that I think I'm throwing hardware at software / configuration issues.

The majority of usage comes from my forum (a hacked version of www.Fluxbb.org ) that is PHP / MySQL based.

I'm on a very beefy VPS that is running CentOS with Apache.

So, my questions for the masters:

1) What information do I need to provide to someone for THEM to determine if they are a good candidate?

2) What information should I get from them to determine if they won't make things worse and are trustworthy?

Basically, I need to find an expert at everything server management / optimization related so I can stop having to throw hardware at software issues.

Thanks in advance for any ideas and/or suggestions.