Welcome to the forum!

Looks like you've done your research in regards to the terrarium setup. It looks good. I'd suggest to moving the Acurite thermostat more to the left so it'll be closer to the edge of the terrarium so you know exactly what the temp on the cool side really is. From the photo, it looks like it's more in the middle. If you need to create more humidity during sheds, you can always put damp moss straight in the hides.

On finding the snake problem, I'd definitely scavenge for sale threads here. There's a lot of good small/medium breeders on this forum. You can always ask people's opinions if you need some feedback about a seller. If you're looking for some decent website, look on the left hand side of the forum when you scroll. You can also check out faunaclassifieds.com or kingsnake.com forums but don't forget to check the BOI (board of inquiry). If you're into auctions you can check out reptilering.com. What BCR suggested definitely works too. Just post a wanted ad and see what happens. You might be surprised and find yourself a pretty morph.

Good luck on your search!