Most people use the FreeS/WAN contrib for creating an IPSec VPN between two SME servers... Is there a specific reason you want to use PPTP?
Also...
"DO NOT use NAT on the client-side, it will hide the network and the servers net
won't be able to route to the client network machines, this would kill network
printing, for example, where the queue is on the server net and the printer is
on the client net."
I assume you are using NAT on the client end as well, though I'm not sure if they mean a NAT-ed client, or a NAT-ed LAN behind the client. Personally, I'd just go with FreeS/WAN for connecting two SMEs...