"Ren Wax" is Renaissance Wax and available on-line. Other members have opined that other waxes work just as well and Johnson's Paste Wax seems to be another popular wax. I can give a thumbs up to personal experience with Renaissance Wax.
I have stored nickel revolvers in all the manners mentioned above and all seem satisfactory but overall I would give a big thumbs up to Bore Stores. For price, practicality, and satisfactory performance old, clean, white socks, 2-layers, is hard to beat.
I am NOT a fan of storing guns in a foam lined case, in direct contact with the foam, as the foam can break down and leave a residue on the guns and the foam can hold moisture that can damage the surface of the gun. Perhaps placing your gun(s) in a sock or two (or Bore Stores), then placing in a Ziplock baggie (getting all the air out, and then placing it in the foam lined case might not be such a bad idea? If you use a desiccant be sure it does NOT rest up against the surface of your firearm.
Myself and many other members have use original Hoppes No. 9 Bore cleaner on nickel with no problem, despite the label (supposedly?) stating not for use on nickel, probably because we don't soak our guns in it and wipe them down well after cleaning. I currently use CLP when cleaning a nickel gun. Read the labels. It's probably not a good idea to soak your nickel gun in cleaning chemicals for prolonged periods and make sure you wipe them off after cleaning in a timely fashion. Nickel seems to be fairly durable and forgiving. A little common sense goes a long way.