As stated above, this is not an either or proposition. If you have your water needs covered an extra container will not hurt.

Water-Crush-Impact resistant, Floats easy to open/rec close and available in your favorite designer colors. Hundreds of carry options as many backpacks, fanny bags, bicycles, etc come with 'Nalgene Bottle Holders' already.

I recently got about a half dozen at $1.99 each from Marshals as they were Polycarbonate with BPA (and we all know that that will kill you all if you just look at the bottle).

I hope you will post pics of your kits. I am still working on mine. I planned to use a mesh bag to hold some items together, but maybe a Ziploc bag will work better.