Developing Embedded Network Device on FreeBSD

[David]

Hello All:

I am new to FreeBSD development (I've done some work on NetBSD, but mostly
on Linux).

I am developing a COTS-based network appliance. After doing my research, I've decided to
use FreeBSD as my development platform. I would like to get my development environment
to the point where I can build a single ISO image that will contain OS and application
ready to install. After reading through the handbook, porter's guide, and googling, I think I have
a rough idea of how to do this, but I still have some gaps in how I set this up.

My current understanding is that all of the application specific, user land software should 
reside in the ports tree. I have two questions with respect to this:

1. If I don't want to publish my software, how do I manage the source (do I just generate a tarball
on my build machine and place it in DISTDIR?).

2. How do I integrate a ports-based application with a "make release" so that I can have my
application binaries and dependancies included on the ISO ready for installation?

I'd greatly appreciate any pointers. I'm really looking forward to developing
under FreeBSD, but just need a few pointers to get me started.

Thanks!

David.