Hmm... Thats going to be tough. I've had good luck in the past by going to google maps, zooming out a little, then just searching for 'citrus' or 'nursery' and going to individual websites of what it locates. Half the time its nurseries I didn't even know existed.

If you are interested in other oranges I have a website you could check out. rgvnursery.com

They have an interesting collection of orange trees available for shipment and they are reasonably priced at $29 for 1 gallon size and $59 for 5 gallon sized plants. Plus the shipping is free.

Here are a couple of the unusual varieties: Shamouti, Skaggs Bonanza navel, Tarocco blood, Vainiglia Sanguigno, Midknight valencia, etc.

I'll keep an eye out for the Sanguinelli while I'm searching today

Here is a link that might be useful: Rio Grande Nursery

Well no luck with the Sanguinelli thus far but I noticed that Brazos Citrus carries the Palestinian sweet lime. They are strictly wholesale but they helped me track down a Kishu mandarin tree a while back.

Just email them and ask very nicely if they can tell you who in your area purchases from them or if they know who buys that type of lime. Thats how I found my Kishu Mandarin tree.