I suggest getting machine oil and keeping the humidity low. If you can save some silica gel packs up, you can throw those in your storage containers. If you really care about them, you need to consider putting them in a climate controlled room.
I bought a gallon of Evaporust last month from Walmart.com. They didn't stock it in my store, but it was around $16.
I've been working on this old outboard engine (currently waiting for a day above 60 degrees that's not windy so I can paint.)
I got a plastic 2 gallon paint bucket with a lid because of its width. With that, I can soak long bolts without a lot of product. The stuff gets pretty dirty, but still works. Evaporust works great to clean up surface rust on stuff. I had a lot of parts that needed it, like bolts, brackets, screws, etc. Takes about a day to fix most parts, but there's obvious pitting on the thicker rust. The chemical reaction turns the rust black, but it can be brushed off. After that, I'm going to use marine grease and coat everything before reinstalling.