I use TightVNC to admin my WHS system. Its better than remote desktop as the session always stays open (But locks the server after a minute).
You can run RDC from Vista x64 easily enough, but I recommend using a VNC client.
I have a AMD X2 6000+ (I used to fold on it) in mine. It runs Twonky Server to serve my media to my PS3, WHS to do my backups and the actual File Serving. Its a solid system which will soon have another 2 1tb hard drive in (Total 6.5Tb on 8 drives). Everything is redundant and if a drive breaks it automatically duplicates to another drive to ensure it has 2 copies. I also run Handbrake on it to copy my DVD's to h.264. Queue it up and it runs happily for weeks at a time.
Not only that, but you have access to all your files from anywhere where there is an internet connection. Windows even handles the DDNS for you!