I hear you on availability to try to before you buy. However, my take, having paddled many different boats, is you really need to paddle a boat for a good week or so to figure out if you like it or not. Almost any boat will feel funny when you first get in it because it's not what your brain and body are used to. I've almost always bought a boat based on written and verbal reviews and specs. Part of that attitude stems from the fact that boats are so disposable anyway. If you don't like it, it'll be broken by the end of the year anyway - and resell on used boats is pretty reasonable imo.
Anyway, Josh D. has a Waka Tuna and being a nice guy I'll bet he'd let you check it out. I ordered a Prijon Cali which I'm hoping to get early June, which you can check out (maybe you can buy it from me if I don't like it
) Zets are a little harder to find right now if you're not in Durango - although I know there's a Raptor around Denver.
Warranties were pretty weak from US manufacturers until Jackson stepped in and did the weighed 3 year thing. My take is if people start voting with their $s and buying boats that are innovative in materials as well as design something might change. Otherwise you're stuck playing warranty roulette.
The good news is, look at your list, they're all awesome boat designs that will fit almost any size and style.