You should have a little more cylinder clearance with the 586. If your 586 has a (Pinned On) Front Sight, you can upgrade to a Fiber Optic front sight.
Speed Loaders: You have 2 Good choices
Safariland Comp III and Jet Loaders
Use HKS for Load and Make Ready
Midway may still have the Comp III's on sale.
I use the Comp III's in my 686 and GP100.
With my K Frame 64 I use Jet Loaders which are just a hair smaller in diameter.
Speed Loader Carriers: You have a few choices. I make the Big Creek Kydex Carriers. You will need 3.
Holsters: Look at a Garrette Industries leather lined kydex. I think you will like what you see.
Ammo: If you reload, I would use a 158-160 grain Round Nose bullet.
Vest: Check out a Duluth Trading "Working Man's Vest". 82014
Also look at the Duluth Trading "Dry on the Fly" Vest 82700
I will be ordering a Dry on the Fly for Summer Concealed Carry my next order.
I carry a Speed Strip in the front pockets for weight so the vest will sweep back better.
I pack my gear around on the range in a plastic tote used for cleaning supplies. The one I have is clear and came from WalMart. It will hold a water bottle, and has Two big main compartment, one for loader speed loaders, and one for unloaded ones and Brass.
Good luck
Bob R
Big Creek Kydex Speedloader Carriers