D-Link basically runs 2 802.11b networks side by side so it doubles the speed (supposedly).

For the actual hosting, I wouldn't even consider running wireless. Its out of the question. Now for other applications (like maybe the accounting department or something) you could do wireless as long as you secure it properly. Servers NEVER go wireless, the other machines you can if you maintain security and are not running high bandwidth things (like large databases) over the network.