It sounds like your main concern is availability of fuel and the size of the container fuel can be purchased.
Alcohol fuel stoves have almost universal availability as it can be purchased as a 12 oz. bottle of Heet in the yellow bottle as referenced by staehpj. This is an alcohol fuel additive for automobiles and is available in almost all gas stations, auto parts stores and big box stores. This meets your concern about availability as well as quantity needing to be purchased.
The next best option is to use your Whisperlite white gas stove and carry fuel bottles to hold a quart of fuel. I do this by carrying two of the medium sized MSR bottles which I think are 18 oz. Fuel for these is sold in quart or gallon sizes at camping stores, hunting supply stores, marinas, and big box stores. If I can find it as a quart I will purchase that. The gallon is problematic. Often a camping backpacking store understands the problem and sells small volumes out of the big gallon can. In the past it was often possible to walk around the campground and find someone with a big two burner Coleman stove and the gallon can sitting beside it. They will almost always fill your MSR fuel bottle if you ask and more likely than not will not charge you for it. Unfortunately, people no longer use the white gas two burner stoves anymore so you see less of this in the campgrounds. The last resort is to purchase gasoline out of the pump. This burns dirtier than Coleman fuel and will clog up the stove a bit over time. However, it is not that dirty and will only require you to take apart and clean your stove a few more times more than you would be anyhow.
The butane/propane cartridge stoves are more difficult to find canisters for. It seems that Walmart usually carries them now in many areas, this is not universal. When they are hard to find and you run out there is not another option with these stoves.