Why not pionerboat Pioner boats -Pioner 17 Flexi
Even this one looks funny:
Did you check highfieldboats in US ?
I have one but only one season so can not give you a hint about long term behavior/problems.
I did also avoid to park it on sand or pebbles. Even in advert. they mentioned - that it is not a problem. This is my first boat and I use it only 1-2 months per year so take care about it as a source of fun for whole family and long awaiting vacation.
If boats made from poliuretan are sand and pebbles proof maybe you can look at pioner boats. There are Norwegian boats and currency rate between USD or EUR and NOK is very good now. Not sure if you can buy one in US