wingbones are definatly not beginner calls, lots of people have a hard time with them. They are however a very nice sounding call once you get the hang of them though limited in use, some people can even gobble on them.
A box call or slate is as easy as it gets. The real hen or the cutter are two good boxes...or a lynch world class. Boxes are as easy as it gets though purring leaves something to be desired. Purring on a wingbone isnt impossible but it's awful close. One of those calls ya need to learn to do. Simple just use your voice. Slates are the purring kings!!! The primo's ol besty is nice with a hickory striker! You'll want something that is waterproof though also especially if you use a box. Carbon or plexiglass peg.
Tubes are easy also though kinda loud (as are all of my wingbones without muffling with your hands, which you can do with a tube). It's also one of those calls not many people use and they are CHEAP to make OR BUY!!! They arent so easy up front to get the idear how to use it....but you'll get it quick, once you do it's an oh duh thing and they yelp, cluck and cut extremely well.
I usually carry a couple box's, a couple slates, 3 wingbones, and a p ocket full of diaphrams.
If you can learn to use a diaphram it's one of the more versitial calls there is, and really not hard to learn.
I'd get a box or two, and a slate with a couple of pegs and you'd be set....just make sure to get a carbon or plexiglass peg with your call, can be slate, glass, aluminum or whatever else they are calling them these days, they'll all work in the rain with the right peg. Just dont use a wooden pot call in the rain to much. You're liable to crack the pot due to sweeling and shrinking.