My 14" Delta knockoff has crowned tiresĀ like most of that genre. I'm not sure about other 14" saws, I've never used any of them.
My Rikon 18 has flat tires, no rise, at least that I can appreciate. I just put the blade on, and have to address the guides to the placement of the tire. I've had them using most of the tire's width on 1 1/4 wide blades,, and tiny little 1/8" which I pretty much centered, and have never had any issue one way or the other. I think if I ever bought another BS, it would have the non crowned wheels. My thinking back when, and still is those crowns are the Devils work, and it's them, and well, that cast iron flexy frame, that cause all the issues with the 14" Delta, and the clones.
My suggestion is no matter what size you want, get a steel frame, something that will take tension. Save up until you can get one, or pay no more than 100 bux for a cast iron flexy frame saw. That way when you finally break down, and buy a steel frame saw, you won't get spanked on resale.