Robbie,
Yes the 1700 series can do IPSEC, but if you dont have you will will need to get either a des or 3des IOS version for your router. IOS is configured pretty much the same way whether your going to anothe cisco device or 3rd party since its supposed to be a standard. Here's a link on how to set this up on your router http://www.cisco.com/warp/public/707/overload_private.shtml
It may not be exactly your situation but this is just one of many samples. If you can get more specific on what you are doing on yous Cisco router, then perhaps get you a link thats closer to what your looking for.
KD
