grovermj - I've started using the Flat Rate boxes - I think they are $8.10 for anything you can fit in the box no matter the weight. They come in two sizes too. You can only imagine how much and what weights I can fit in one of those suckers!!
Goodness, yes, loads of HP nerds and geeks around here. C'mon around the swap board and visit! We do lots of HP swaps and would love to have you visit and join in! Lots of bags are made, but none like yours yet! They're beautiful, I love the straps.
I think that photos if possible would be awesome. It really would give a good idea of space and placement and maybe spark ideas for items not mentioned!
2 big and 4 small sound great to me, with a mixture of purchased and crafted. Sounds like you're pretty good with what you've said so far! I can't wait for this one, I'll have to keep an eye out for signups.