The tool decisions will wait until we have a core of developers and then the entire group will decide. I will get the best rip I can of the m0n0wall svn, and so it might make sense to go that way, but there are some advantages to github as well.
Either way, I am a big fan of letting the artists choose their tools!
Well I had used m0n0wall in my project and I did lots of modifications in it ... So I'm comfortable with their code as long as it deals with Shell Scripting, Php, little bit C because I'm intermediate in C. So I can work in that area.
I'm still not done with the project ... i'm working on it may be by this year end it'll be finished. I didn't used PF Firewall I went with IPFW. And no I didn't have any sort of performance issue till now.