Wow. Conceptually sound, but that thing is 6 pounds before getting loaded up! Regarding the rev bag II, I have one. I don't like the fabric as much as the original. And, one of the Velcro strips to keep the flap closed tore off the bag about a month after I started using it. I still love the bag though.
I use a Rev bag and the only thing I found a little weak was the outside pocket zipper. It gave up this spring after years of use. I have 8 Revs,1 glider, various line sets and handles, and 2 cardboard mailing tubes for frames. Take out the tubes = 2 more kites. You can get 2 per sleeve and maybe even 3 in the bigger one. I put a second strap on mine to be able to carry it like a backpack and leave my hands free for other stuff.
There are other good bags out there! Kite Connection, Ocean Shores kites, short bag from ITW, etc. Really depends on you and your budget.
here's an option I have found end enjoyed recently. A hard sided case for fishing poles from Orvis
180 bucks, it doesn't hold a Zen either unless you have a travel frame. It does hold a ton of stuff and it is well protected and easily transportable
Separately Brianne (Howard?) will make a custom kite bag for you, exactly as you design it,... want a dry place to sit down?,... she can affix a fold-out panel just for your tail feathers. Want a spot for six sets of handles with lines in place? two parallel rows or a single stacked column? You can see examples as inspiration,.. her effort is a couple of hundred bucks. Want a tow strap, funky handle locations on the corners, whatever you can imagine, obviously custom embroidered too. Several friends have her stuff it is envy making every time I see 'em.