Bag Help-- 2 bodies with mounted lenses

[Headshotzx]

Hey guys! Santa's a little late, but he's personally promised a 70-200 2.8IS on the last day of the year!

Alright, so my normal go-to kit would comprise of the gripped 400D, 17-40L, 70-200 2.8IS and one 580EXII. That's no problem at all for my Lowepro Primus AW.

It's only when I'm shooting seriously, when I have 2 bodies and 2 flashes, that my problem comes in.

So here I am asking-- what bag would fit:
++Gripped body + 70-200 2.8IS mounted + hood
++Ungripped body + 17-40L mounted + 17-55 hood
++2xflashes, either internally or externally
++Water bottle, either internally or externally

My first thought was this (excuse the disproportionate sizing):

Above, in a backpack (front view) or in a shoulder bag (top view)

and my second thought was:

In a shoulder bag, front view.

Does anyone have anything in mind? If the bag has a sliplock / additional mounting option, I can use my Lowepro 60AW for the 2 flashes and / or my lowepro water bottle bag.

Cheers,
Zexun

[Reportage]

how about getting a messenger bag or backpack and simply put everything in it. Not glamourous but works and is cheaper too.

[Headshotzx]

I'd want the padding, and iirc the cost of the padding + the bag + not knowing if the bag can take the weight would probably be close to a dedicated camera bag already.