I've been thinking along the same lines, but decided to buy a "Trial kit" first. Then I'll know that the chemicals and paper are good. When I've finished with the chemicals in the kit, I'll probably change to D-9 or something similar.

From a quick glance at the formula, the keeping properties of D-9 should be very good.

As to how it works, there's an introduction on http://unblinkingeye.com. I can also recommend Tim Rudman's book on the subject.