Hickory is better suited to back than to belly. It will take more set than osage as a belly wood all else being equal. Generally for a core wood it's considered best to use something which is lightweight to reduce the mass of the limb, but anything you listed would be fine for the core. Considering you're new to the game of making bows, I'd imagine the minor differences in performance form the different core woods will be largely irrelevant to you.
Personally I'd go hickory backed osage, with whatever core you think will look the best.
Consider this however ... if you're going tri-lam you may need to taper the core lam so that when you thin the belly during tillering you don't cut all the way through it into the core. or thin it so much it doesn't match the three layered look of the inner and mid limb sections.