I am looking to replace 2 domain controllers.. 2 x windows 2003 R2 Standard 64bit. Both are running AD for the domain.. One is running DHCP and is a DNS server.. There is no secondary DNS on the network. I am looking to be fault tolerant for DNS, AD and DHCP.. The 2 x windows 2003 servers are also File and Print sharing servers... Any thoughts on what I should do to upgrade these 2 servers... I am thinking about 2 x Blade Servers, and a 2 TB SAN. Thoughts? Suggestions?