Just about any true VPN solution won't by-pass firewalls on the in-coming side... (Where the VPN "server" sits)
Open VPN can run on windows, Linux etc. and is extrememly reliable, especially compared to IPSEC VPN.
I have a client who is using VPN over a SATELLITE up/down link! These satellite connections have notoriously bad lag time, making IPSEC almost impossible to implement, the Open VPN works flawlessly. The same server that is handling incoming for half a dozen home users is also handling 3 "remote offices" each with a dedicated VPN connection as well as acting as their gateway/router to the internet and a fiber connection to another agency. This same client has a 2nd Open VPN server (Seperate because this part of the agency requires FIPS compliance in their VPN solution) handling 15 mobile data terminals used in their police cars utilizing AT&T Cellular cards in the laptops, and one DARE officer in a high school with extremely tightened-down security going through a proxy server (had to default the DARE officer to TCP instead of the more efficient UDP protocol).
I haven't found a situation yet where you can't get a stable connection.
(If you have to have FIPS level security, it's a bit of a PITA to set up, since you will most likely have to compile the FIPS module seperately... and un-install the non-FIPS compliant OpenSSL modules that will likely already be installed on the system. I didn't have too much problem with gentoo, except until I got all the install locations in the correct spots, SSH wouldn't start up, and when I was doing this I was using an SSH session to connect to the server.)