If you are purchasing a custom call, I would talk to the call-maker and go off his/her recommendation. The single largest benefit of ordering a custom call from a custom call maker is... Well customizing it.
If you want something that sounds a bit different, I might also consider a scratch box call... Some of the best cutts, clucks, and purrs, and a unique sound to the yelp (which I do feel is very realistic after some practice).