I'm looking for a bit of advice on buying a hardware firewall for a small network with a VPN to our branch office.
We already have a couple of Cisco 837 ADSL routers, which for various reasons (they're supported by our contracted warehouse, and have a VPN that is administered by them as well, as well as a lot of custom configuration) can't be changed, or reconfigured at the moment. What we need is a firewall that will work with this router and support around 25 users, with decent VPN capability at a price that won't break the bank!
I've previously looked at the Symantec/VPN appliances, and the Firebox series, but we only really want to spend around £300 or so. Ideally I'd like something like the Draytek Vigor series as I have some experience configuring them, but we obviously don't need the ADSL router part of it, and they don't do a standalone firewall like some other suppliers.
Any tips on a box, and where to buy it would be greatly appreciated.