I just moved to elk country two years ago, so I have only been chasing them for that long. Dreaming of them for much longer though... Anyway, take my advice for what it is worth, that of a new elk hunter.
Diaphragm calls are really where it is at. They are cheap, small, hand-free and the variation of sounds is second to none. I have the other calls, and have never gotten so much as a response from them. (perhaps I suck at them, honestly) But using diaphragm calls I have called one very nice bull into bow range (Frankly, I'm not really ready to talk about that one yet....) and two different cows to within sword range. Seriously, I had to stop the first one with a whoa so i didn't get trampled (bull only tag both times...). There are a bunch of different makers and you should be able to find one that fits your pallet. They are weird at first, and it took me a couple days of trying before I could make a noise that didn't sound like someone trying to kill something with an elk call, but they are pretty awesome.