keyserver choices out there?

[Michael Cunningham]

Hiya,

I am currently in the process of exploring 
setting up OpenPGP for my company's use. The 
execs are tired of the rumor mill knowing about 
things before they do. They need a way to encrypt/decrypt 
their email when using outlook. I have been playing 
with G-DATA GNUpg-plugin for outlook and everything seems to 
work well (anyone know if they plan on updating it?). 
I now need to figure out an easy way for 
everyone (hundreds of people) to exchange public keys.
I am looking for a keyserver that has the following features 
if possible: 

1. Web based interface so users can upload/search/download keys. 
2. Ability to create and offer for download an entire keyring.. 
    Example: Search for all keys with the keyword "xpedite" in 
    the email and produce a keyring that folks can import directly 
    into GNU Privacy Assistant. 
3. Easy or at least not too complicated method for admins to remove 
   keys from the keyserver. 
4. If possible.. the ability to export a key directly from GNU privacy 
   assistant directly into the keyserver. 
5. Free, and opensource if possible. 

Can you suggest what would be the best keyserver to use in your 
opinion? I want to set one up internally in my company. 

Thanks for any assistance you can offer.. 
Mike