Hi Mattio,
A few thoughts just as a daylily buyer, and not a seller or hybridizer (other than for my amusement).
The idea of your beds along your long driveway is a great one. It would be seen from the road and would be good advertising and also would encourage people to stop on the spur of the moment. Daylilies are so beautiful en masse. Also it will beautify the entrance to your b and b.
I would purchased named cultivars from reputable sellers. They don't have to be the 'latest and greatest' to start. There are many very beautiful older varieties very reasonably priced. Our members regularly sell off extras for great prices and I am sure you could get a lot of wonderful daylilies from them. I do think you should get good plant markers to keep everything well marked. Most people like to know the name of the cultivar, even if they eventually forget or lose their marker :lol
Anyway, good luck. The draw of a renovated farmhouse with gorgeous daylilies should prove successful!