There's a particular variety of Yuzu called Hana Yuzu, but it's nearly impossible to find outside of Japan.
Yuzu also isn't a direct hybrid. But if you wanted to try creating your own new hybrid of "Yuzu", you could try crossing Citrus ichangensis with a mandarin like Satsuma, or a sour mandarin variety (which aren't too common).
Still likely to have lots of seeds. If that's primary issue, there are ways around that but it's too complicated to bring up here.
Also what you have to realize is that Yuzu is not quite used exactly like a regular lemon. It is not so much valued for its juice as it is its fragrant rind. And that rind is a little bit more tender, edible and less bitter than the rind of an ordinary lemon.
Slice the Yuzu, remove the big seeds, and then dice it all into smaller shreds, not removing peel. Many culinary uses, flavoring sauces, or for baking.
In Japan sometimes they press the Yuzu to remove the juice combined with the fragrant oils from the peel, probably a good idea to remove the seeds first before pressing (since crushed seeds might impart a slight off flavor). If you go to a large Japanese market you will be very likely to find Yuzu extract (it might be mixed with salt to help preserve it).
