I've been watching this discussion with interest, having spent three
years packing in the jungle backcountry of southern Mexico. Packing
wierd shapes, sizes and weights on mules, or porters, and carried on
narrow steep slippery trails. Has the OP in this discussion described
where he plans to carry this bag? Are you traveling in the air travel
system, and what countries? Or are you looking for something to store
the cat in at home? Are you planning a portage, and how long? Are the
measurements you give required to fit in one bag, and how much would it
weigh? Or would you be better dividing the weight?

Baggage handling machines eat backpacks with all the loose straps, for
lunch! Catus and thornbushes can shred an inflatable while being
portaged!

I'm with pmhilton on this one as far as keeping it as simple as
wrapping the bits in a tarpulin, bundling with ropes, and attaching
shoulder straps, or tumplines. Packing can be individually monitored
for weight and size. Bundles can be strapped to mules, and porters in
foreign countries are use to carring bundles, but not backpacks.

Even if you are storing in the garage, a tight bundle will be easier to
handle. Also when you get to where you are going, you unroll the
tarpulin bundle such that all your equipment is still on the tarpulin
and not in the dirt and oil of a parking lot or streamside mudflat!

Now on the otherhand, if you show up at the local waterhole carrying
your stylish equipment in a stylish backpack, I grant it will make a
better impression!

Just my two cents worth, TnT