Getting a new server, suggestions to handle these specs?

[bobbleheadR2D2]

Getting a new server, suggestions to handle these specs?

What level of server do you suggest to handle the below.

AKA, processor, ram, OS, and if you really want to get crazy, optimization specs for PHP and MYSQL settings.

30+ Domains - most with little to average average activity

2 or so VERY active - MYSQL PHP heavy

PHP/MYSQL heavily used, PHP on almost every site.

PHP includes used on many sites, pulling flat file info and
header/footer/sidebar files into a main page.

Run 2+ Vbulletin Message Boards,   HEAVILY modified above and beyond core installations

Mod Rewrite via .htaccess used  heavily

Sites usually graphic intensive on top of all PHP/MYSQL needs

Some sites serve large static files such as MP3s and MPEGS, rushed at times
when new content added.

Need to serve MYSQL driven board systems with 1000+ users accessing large static files such as JPEGS, MP3s, MPEGS THROUGH the board system, via attachments and direct links to server files.

So, what do you all suggest to handle such a set up?

[SensoVision]

first of all welcome to forums, bobbleheadR2D2!
Although I'm running Debian box as my OS, I've never dealt with true servers from the hardware specs side maybe someone who run hosting could help you out.
But I would start choosing a server from a question to hosting company(if I understand you correctly you wish to move sites from other hosting or I'm wrong?) who did host these forums before, it would be good to check their stats and see how heavy was load on the servers before and did the hardware handle it easily. I think it would give you very useful information, of course if hosting company could present you such statistic.