Propane fireplace hook up

I know this is a gas install. I will be doing it myself, but ultimately will have it looked at by a family member who is a plumber. Sounds crazy, but I'm doing the planning and research myself. I enjoy it, and I want to minimize the "favor" that being said, this is my situation.

I'm installing a new LP fireplace. directly outside of the fireplace chase will be the propane tanks. I plan on putting two 40lbs tanks out there as they are less obtrusive and still easy to bring out to refill myself while having some decent capacity. Ive been seeing info about auto switching regulators and am very interested in using that feature. from what I've read, i'll need a two stage regulator system and most of these auto switching regulators seem to have that feature (need 11"WC) but its a matter of getting a quality one i can rely on.

my plan is to run what will most likely be no more than 2-3' of galvanized pipe to go through the wall to the appliance. Inside, I plan on using that corrugated line to connect to the fireplace (or whatever you think may be better). On the outside though, from the regulator to the two tanks is where I'm not sure what to do. because they're smaller tanks they seem to only have the type of valve the a BBQ tank has where you screw it on. I want that convenience for when I take the tanks to refill, but what type of hose should i be looking for to go from the regulator/switch to the tank? these will be exposed to the elements ultimately.

let me know if you need more info before you answer. theres really not much to this setup I think. its a very short run, and its one appliance.