Hmmm…are there any you could try, though? It’s tricky when you know you want something particular because you might not get it if you order online.
Out of the two on that list I’ve tried, the FH dynamic range is spectacular but it is a very bright sound, moreover, the brightness does vary from harp to harp so where one FH might be too bright another might not. The closest other harps in sound to these are the Salvi ones, if you’ve ever tried one of those.
The LH I would describe as high tension, dull sound. Many people adore them though (“mellow” if I was being nice:) No idea what a Blevins is like, they don’t import them here.
I can’t stress enough the importance of trying though. Maybe there are other harpists on your area that might have some of these?