On Respirators:
Whatever you get, the standard required by my EMT School for medical particulates is a NIOSH N95, which can be had at Home Depot. If you want to go higher the P100 rated masks are significantly more expensive (like, 10.00 each) but they filter smaller. For debris, something lightweight and cheap, the N95 rated mask is the way to go...properly fitted. Facial hair will screw you at the points where the mask contacts your face, just to be noted.
We found our rainsuits on Ebay. Everybody sells everything on Ebay. We try not to be junkies but that's just where stuff is.
As far as medications...
We buy small pill-bottles from American Science and Surplus and just put the regular bulk medications in them. Either that or miniature ziploc bags from the swap meet (We won't speculate as to what other people do with these) can be used for a single or double dosage of the medication of your choice. This makes the most sense logistically, especially if you're smart and writing your expiration dates on the outside; That way you can ensure your stock is rotated, and if you use it, you can replenish it from an already existing master supply without paying some company for packaging.
Something Sarah and I have learned is logistical compatibility from Master Storage down to Bugout Bag. EVERYTHING is refillable. Disposables, while convenient, are only of limited utility and generate waste; Plus once they are no longer functional, something else new must be acquired to replace it.
There are pros and cons to the 1-use-disposable theory vs. multi-use-refillable theory. But when you're maintaining a logistical supply chain from Master Storage, to Bug Out Vehicle, down to Bug Out Bag, refillable makes more sense.
Panz