(Urgent!) VPN through two firewalls

Here is my situation.

Our old firewall died and we need to replace it. Our outsourced "tech support" wants us to buy a $3,000 Cisco router so we will have a DMZ port for our FTP server.

I think this is overkill for our small business of 30 or so users. I proposed we use two much cheaper Cisco routers (ASA5505 - $350) to create a DMZ like such:

Internet --- |ASA5505#1| --- FTP & |ASA5505#2| --- LAN

The question I got asked was would we then be able to VPN from the internet to the LAN. I have never tried this and while both firewalls are capable of VPN I am unsure if it will work.

Is it possible to VPN the way I want to? How would I go about setting that up?

Thanks!