Its very hard for anyone to really evaluate your needs from this forum. But I can say a couple of things.
I have seen MaitreD and I like it a lot. It is stable and easy. I have no idea how it handles cashiering, so that may be your key issue.
I also don't know how it does inventory, but it MUST be better than Aloha for that. Aloha SUX0rs in the Inventory arena.
But Aloha does handle Cashiering very well.
Aloha is a much more established software, meaning that it has been adapted to meet an outrageous amount of environments. -Good if you need flexibility, but most people use about 3% of its capabilities. -Bad because it gets complicated to setup and make it work exactly how you want it to.
Training on Aloha is the easiest for your FOH employees because it is so widely used, most people have used it many times before.
If Maitre'D meets your needs for Inventory and cashiering, the next steps are the level of service you will expect from the dealers, and then of course $$$$.
{how's that for a big 'ol "non-answer"!}
I think Matre D is a very good and stable product. Have each dealer setup a demo for cashiering and inventory specifically. These are your two key issues.