A 22 WMR with hollow points would be a good light caliber for any Predators/Coyotes,the .223 would do even better using a light bullet in say 40-45 or the 55 grain Hornady V-max bullets which I use in my Savage .223 bolt-action!
Snow Camo is nice but not necessary if You have regualr Camo and use a Cedar tree or thicket/bush for concealment.One of the Outdoor Life or other Hunting/Fishing Magazine did a nice Article on cheap Snow Camo,they used those light weight throw-away white shirts and pants that You can buy for painting or dirty jobs and lightly spray painted them with misc Camo spray paint and used them over Your exisiting warm clothes to hunt in Snow!
Personally I use the simple mouth calls for calling in Predators or the cheap portable Johny Stewart Predator Caller that has about 5 sounds on it for about $35.00.Another simple item/decoy to use is simply a long dowel rod/stick and put a colored feather on a short string and stick it in the ground out in plain view!I think Johny Stewart also makes a nice foldable one (Feather Distractor) to catch the attention of a Coyote,Bobcat or Fox...and it works!I've had Coyotes come in to my Calling and their attention was on the Feather and they ended up with 39 grains of Sierra Blitz King .204 bullet in them!
The following Mouth Calls work well just about any where.
Knight & Hale Cottontail Distress,Knight & Hale Jackrabbit distress,Lohmans "Circe" Jackrabbit,Primo's Katnip Caller for Bobcats and any good Fawn in Distress call...the Primo's Lil' Dog open reed callers in a small green Call and larger white/black Caller for howls and barks!