While I would certainly like the opportunity to earn your hosting for
Caro.Net I have to agree with Rowan's wisdom and insight.
Beyond the RAM upgrade you might investigate your network connections a little bit. While 2000 GB of transfer and 10 Mbps Private LAN connections may be plenty for you, look to take advantage of your 1 Gbps NIC's with a minimum connection to your supporting network of at least 100Mbps.
Good luck with your upgrades and if you do search further please keep me in mind, Caro.Net is the network home to AEBN and I would certainly do my best to earn your business.
Best of prosperity in the New Year!