Polar Pure is the closest to what you are looking for in a mobile configuration. If you are talking ten, twenty gallons at a shot, then your best bet chemically is either potassium permangenate (tricky, finicky and annoying) or bleach (stinky, but if it doesn't stink, there is still something to kill- let it air out overnight and add some vitamin C to it tommorrow). But I can't think of anyone who's done bulk purification with iodine, because of the thyroid issues that can pop up if it is used for more than a few months.

Oh, and iodine makes crypto giggle- the spores think it tickles. Chlorine dioxide, 1 micron filters and boiling will get it, in order of increasing effectiveness. Iodine was the hot stuff 40 years ago because it was that or halazone which has it's own issues, but against a heavily armoured spores (like crypto and anthrax, if you are in cattle or punk rocker country) and possibly some protozoa (nothing in North America is in that group, though), it doesn't do much. If anything, it probably contributed to our rates of dysentery during our stay in SEA because people thought it was safe rather than using boiling.

I know there are small scale purification systems, designed to be use at the village level, but I've never seen them. That might be your best bet at this kind of volume, but I don't know about portability short of a small truck. Either that, or a good fuel source, and a big pot, if you want to do 10+ gallons at a time. It might also be possible to do something like the Miox system, just bigger, but I haven't seen them.