I would recommend going 2008R2 as it is the latest and greatest. I haven't compared memory usage specifically side by side on both the mentioned OS's but you shouldn't see a difference.
Linux & Windows Hosting Expert - Lead Sales Engineer @ BlackMesh
Highly available enterprise cloud and physical hosting with 24x7x365 US based live support (IaaS/PaaS) FedRAMP Moderate, DISA Level 2, FISMA, PCI, HIPAA, and SSAE 16 certifications [email protected] -- 888-473-0854 x720 -- www.BlackMesh.com
Thannks guys. My current home server runs 512mb no problem running server2008 32bit with some asp.net applications. My vps will either be 512 or 1GB and I may run a mail server and more sites on it.
My concern is server2008 R2 being newer will naturally consume more ram plus extra overhead being 64bit?