At work (not cuemaking) we have one of our lathe's set up with a Dorian BXA piston type toolpost, and another set up with Aloris AXA wedge type. Dorian is top tier, like Aloris. It works just as good as the Aloris.
I'd personally go with whatever you have in the rest of your shop. This way you can standardize with one size throughout the shop.
AXA are also more common, and may be cheaper to buy the toolholders if you go the ebay route in the future.
On the flip side, if you have two lathes with different size toolholders, its impossible to mix them up, and you can leave them set at center height. This is what we do at my workplace, where we have many users of different abilities using the lathes.
At home, I have the import wedge AXA set. There is no comparison to Aloris or Dorian in quality. If you can swing it, get the real deal, especially since you will be touching this area of the lathe every time you use it.