Should I contact my old cat breeder?

I’m sure you’ve experienced this before:

When making a big purchase that requires a decision on which company to use, after making a bunch of phone calls/emails, you begin to bond with someone. Then, almost inevitably, you go with someone else.

Do you let them know you’ve gone with someone else, or do you wait for them to contact you first?

The specifics: When deciding on my new Exotic Shorthair, I sent out over 60 emails to breeders in the US. One cattery (yes, they’re called ‘catteries’) stood out among the rest for me. They were extremely helpful, even though they didn’t have what I was looking for at the time. They answered all of my questions, and expected to have what I was looking for later in the year, which was also going to be when I would have space for the new kitten. My circumstances changed, and when I was able to get a kitten immediately, I began looking at other breeders out of curiosity, and fell in love with a kitty that I now lovingly know as “Lemon”. After months of speaking with them, and sharing our lives’ stories, I can’t help but feel a little guilty on the matter (I’m also neurotic, so that doesn’t help).

At this point, would the situation warrant a, “Thanks so much for all your help, but I’ve gone with another breeder,” or would it be better to wait until they email back with a potential kitten first?