Ebay should have something like "netting" that can go around the bottle to protect it from scratches and minor bumps. Search the SCUBA stuff.
I don't know of much to make it stand upright. Generally, round bottom tanks are used laying down. I built a jig to hold mine a while back. Using 2x8 lumber, I made a basic "U" shape and cut the ends to cradle the bottle. Then, I used sticky back velcro on the bottle and the jig. The jig stuck to the bottle, the bottle wouldn't roll, it was high enough to make the valve easy to access, and I ended up with a little accessory shelf underneath!
Sorry, I don't have any pics. The bottle does not fit in the center of the "U", it fits across the ends. If you hold your bottle in front of you horizontally with two hands, you'll see what I mean.
Tom