Invertz Factory and Frank's Aquarium are both selling S. resplendens. I've never purchased from either of them, but I know that Frank has an excellent reputation. He isn't shipping out right now (cold weather), but I think he will be soon.
Best of luck!
My order from Frank is pending shipping, so let me know if you want a review on the process. So far he has been nothing but courteous and helpful and I don't expect that to change come shipping time. I've heard only the best as well.
I've gone back and forth with Frank in emails and on his bulletin board -- he's super knowledgeable about his fish and truly cares about the hobby as a whole. He quarantines all fish that come in, and he doesn't send out anything that's been exhibiting symptoms. In short, he's a great guy.