If you just want to carry the 901 and a couple
batteries, and not EVERYthing you own, You could go to the local Smoke Shop/Cigar Store, I am sure they have plenty of Old Cigar cases with the screw tops that top end cigars come in, you might get them free even.
Some of the shops here have smoke rooms where people can test them, they most likely just throw out the casings.
Just a thought.
The best Idea is still to get a leather Cigarette pack case, and a piece of craft foam from the craft store.
Use something metal like a screwdriver, heat it with a propane torch, or candle flame, and make holes the size you need in the foam.
Its safer then the spray in kind of foam, and holds its shape/and holds together better. You should be able to make holes for a bottle of
juice, a couple batteries and an atomizer or two. A lot of them have belt clips too.
They even have a place for a lighter on the outside normally, where a bottle of
juice should fit fine.
They can be had for next to nothing and found at the Dollar/cheap stores.