Re: Looking for gas can
MSR makes one fuel bottle that is the same height and only a tiny bit fatter than a regular bicycle water bottle. It will not fit in all water bottle holders, but it will fit in the ones that grab the bottle "sideways", if you get my drift. So you may need to buy the fuel bottle and then take it along to bike shops to find a water bottle holder that it will fit in.
Also I have noted a problem with the MSR fuel bottles before: I had some fuel I left sitting in a closed one for a couple weeks, and the cap swelled up so tight that I could barely twist it out. Since the cap/loop is one piece molded plastic, if the loop breaks off you've got no way to get the cap off then.
What I have heard is that this (cap swelling) is caused by the alcohol now mixed into USA gasoline. It is only a problem if you LEAVE the gasoline in there for days at a time though. So now you just only put the gasoline in right before you ride, and pour it back out into a regular gas can after the ride.
Thirdly,,,, why not just use a regular soda/water bottle? Because (US) gas stations won't let you put gasoline in them. Every US state now has laws saying that you cannot dispense flammable fuel into a container that isn't designed for it. Since the MSR fuel bottles are marked as liquid fuel containers, they legally qualify as gas cans.