Yep, historically they tended to have one axe-blade, not two. But if the "movie look" is more of what you're after, then it's entirely up to you.
Some of the longer poleaxe weapons historically had a hammer-head opposite either an axe blade or a spike of some sort. The idea here was to have something versatile, with a hammer for bludgeoning the armor, and the axe or spike for cutting into joints, or pulling armor apart.
I'd definitely look at the KoA link that Sir Ian posted. The site has a good prices, and a good selection, and their customer service has always been great.