Dean, do you leave your rice in another bag before you seal it? I have always put mine into a cheap ziplock, left a bit of the seal undone(or taken a fork and poked one or 2 holes to let the air out) and then put it into the vac bag to seal. If you get good results, maybe I can skip this step.Net's suggestion is exactly what I do.
I buy bulk bags of rice from Sam's and vacuum seal the rice. Then put them in sealed containers. About to buy some moisture packets to soak it up. It should preserve the rice for at least 2-3 years from my best research.
Mylar bags,When you say mylar what you mean exactly? Are there special mylar food containers?
What effect does light have on sealed food?
You can get dry ice at any icehouse/ice supplier (which means being in an urban environment usually), and it's not nearly as dangerous to work with as most liquid refrigerants.Dry ice is also a little dangerous to work with and hard to find.