Dawn, a couple of thoughts for you.
I have bought two of the "jiggle" pump/siphons, and have since junked them both. In my experience, when you really need them, they have a tendency for the little plastic ball in them to get stuck, and not work at all. I replaced them with these pumps out of harbor freight.
http://www.harborfreightusa.com/usa/ite ... t2=find+itAdd longer hoses if you need to. They are about $6.00 each, and I keep them in separate ziplock bags marked with water and gas. If you don't keep the gas siphon in an airtight container, it will make the inside of your Jeep smell like gas after you have used it.
I do keep two cans on the carrier of my Jeep, one gas and one water. I have used the water can for camping in locations without water, like Mormon Well campground. Totally worth the expense and effort to be able to spend two or three days up there.
Opinions and "where to buy" ideas for cans and carrying systems can be found here.
http://home.comcast.net/~sday77/binky/b ... rycans.htmBut, as I said, this was from my experiences, and yours may differ according to your individual usage, mileage may vary.
Travis