Which VPN do I use for a Cisco VPN concentrator? I want to setup corporate sync on my DroidX and it appears to work until I try to get email.

My office uses Microsoft Exchange.

I think I need to set up VPN to do this? (not sure, I know I have to use vpn to make outlook work if I'm not on the network)

Which VPN selection should I use? We are using a really old Cisco VPN concentrator that I don't know much about, with a Microsoft shop for pretty much everything.
With a "really old" Cisco VPN concentrator, there are pretty good odds that you can get by with a PPTP tunnel. Especially if you're relying on the native Windows client from desktop/laptops (XP?).

However, with Exchange in the mix you may not need to establish a VPN. My new employer runs exchange and I'm using the "Mail" app to connect to it with no fuss or muss. It "just worked" after I plugged in the external mail server address (mail.mycompany.com) and my domain creds.