I like Singing Tree Gardens Nursery out of Oregon. They won't be shipping to the east coast until fall, but you can order now. And, if your order is $149.00 or more, shipping is free.
Singing Tree Gardens Nursery
To date, I've purchased 6 rhodies from them. Their selection is great, with a lot of unusual colors. The plants are removed from their container and shipped with the root ball wrapped in a plastic bag. They put bamboo stakes in the root ball and trim them to fit the size of the shipping box. This prevents the plant from shifting too much during shipment and destroying the foliage.
You can sort based on color, hardiness zone, ultimate height, etc. If there's something you want that is out of stock, you can get a reminder when it's available again.
As I said earlier, order of $149.00 or more ship free. As they are in Oregon, and the plants are shipped with soil, it's worth getting several and even asking friends and neighbors to go in on a 'group' buy.
Singing Tree Gardens Nursery