Printing over a PPTP connection works fine. I have it set up that way at my company, as well as more than a few of my client sites. I would suggest you use a hypervisor such as MS Hyper-V($$) (2008 R2 core install) or vmware ESXi/vsphere (free). This gives you a bare metal virtualization platform. Then, virtualize 2 servers; 1 for AD and file sharing, and 1 for RDS. I would suggest at least 1 quad-core xeon CPU and at least 8GB of RAM. An HP Proliant ML350(tower) G6 for DL360(2U Rackmount) would suit your needs perfectly.