Hold on there cowboy...
Macs have RAM limitations as well. Mostly based on the type (H.W.) you buy. For example miniMac is limited to 2GB, iMac 4GB, and you can find the rest at
http://apple.com
Looks like Mac Pro is 64-bit. Runs both 32 and 64 bit apps.
Who knows what the actual dVerb count is? If you put a bundle on the a MacPro with quad Xeons (Damn Xeons, same processor used in High End Wintel Servers). I don't think you will care what the dVerb count is, will not be an issue.