Re MDinana

I think it is quite difficult to get the 24hr Ration Packs in the US. (the gear practice asummed a UK-US currency parity, as everything in the US is cheaper and the US has less sales tax etc, although at the moment the dollar/sterling rate is quite high).
In the UK the it is much more easy to get the 24hr Rations. I am quite lucky in that I can get the ration packs at Tams Army Surplus nearby.

http://www.tams-army-surplus.com/products.htm

The main problem is the postage and packing costs from Internet Suppliers. The cheapest can be had on ebay but they can also be brought from some internet retailers for about £3.50/ration pack but once you include the postage and packaging the price works out about the same as Tams and I know that the packs are new.

I don't think it would be economic to have them sent to the US from the UK.

Trade Volume discounts may be available at

http://www.farsm.com/ration_pack.aspx

But I suspect that the shipping costs would be very high and you may have to deal with USDA as well.
You may occasionaly get the odd seller on Ebay in the US.