Delays often happen with harps, but the dealers “not being very nice” is just…not nice. If you are uncomfortable with them, there are other dealers around if you decide you want to stick to L&H. Or buy direct from them. There are a couple of gurls there that are really lovely to deal with.
There are differences between Salvi and Lyon and Healy, but which you like is very much your taste. What I will say about the differences are all very much generalisations – and from a players perspective – mine!
Salvi tend to have a warmer and more focused sound, and a good one has a typically bell like purity in the upper register.