We've got a fortigate 60 firewall which is sadly non-UPnP. I want to open it up so that I can get at my office Mac with BTMM. Any help? As far as I can tell, if I open up TCP destination 443 and UDP destination 4500 it's supposed to work.

I would suspect that NetMine at $29 is probably missing a few of the features that the "Fortigate 60" Firewall at approx $1200 has.
But I could be wrong...