Seeing Blitz has now bit the dust, but don't be surprised if they go off shore, you may be interested in ROTO-PAX. http://www.rotopax.com/home.php Now even a dirt bike can carry extra fuel and water as well as other items in a pack designed to fit most vehicles. A container designed to lat flat or at a 45 if needed. Cost? What's your life worth.
Afford? Ever needed a drink and then found out that old milk jug you'd stored your water in sprung a leak? Or faced a head wind of 60MPH in the desert on a Triumph that caused you to use more gas than you calculated? I have, lessons learned the hard way are seldom forgotton and afford is relative to the end result.
44 to 99 USD for a 1 to 4 gallon gas can. Neat form factor. Cost? Dropped a duce when I saw the price point. Metal gas cans (5 gallon Jerry cans) are still avalible, updated even - Even at this - the can is 44.99. Uf-dah! Surplus cans go for $20 USD /1 gallon and up. Not 'legal' in all states. Sportman's GUide has 20L gas can for 25.17 and the 10L goes for 19.55 - the spout goes for about *8 Again, not 'legal' in all states. Still lots of choices, but I have to admit the roto can are as slick as they get and very popular with the long distance motorcycle browd. Sportsman guide has USGI "style" cans for
Living rural I have collected and use a variety containers. At least one of each type you posted as well as other of the "approved" type with spring loaded lids. Best rig I have a set of the German style (above) and a German angle iron rack thatpad lock's the cans in place as well as the lids shut. Never had to walk for gas but I have had to push a motorcycle uphill once. Read more: http://www.survivalmonkey.com/threads/roto-pax-a-better-portable-plastic-container-fuel-water-or-other.33967/#ixzz20FPGdPCM
I have to admit that these would be nice to have but, at those prices I'll pass and keep using what I have.