1) How many websites could a server like this handle on a 100 Mbps synchronous line?
2) Are there any colocation companies that would hook up to the fiber card for connection?
3) What is the best choice of action when dropping line to in in a colocation center? The dual on-board or the Dual Intel Pro/1000MT? I know that there is load balancing on the on-board Broadcom NICs but how do you use them for load balancing mode?? Then are seen as two separate NICs. I can drop as many lines as needed in the data center I am planing going into so number of lines is not an issue. let me know the best action on connectivity for my server with my specs provided.
Why do you need one big server to host many sites? seems to me you are putting all your eggs in one basket, if anything happened to your server all sites would be down you would have to scramble to bring it back up, this is my understanding from your question 1), it would be much more cost effective to setup several small server and add more as needed, just my opinion.