Normally I try to find them locally, avoid the stress of shipping. If you're in denver, Ambrosio aquatics had some a couple weeks ago, saw them at the reef builder show. If you order online, I had a great experience with extreme clownfish. Alex is just down the road from sea and reaf hatchery, so that also helps avoid added stress to the fish.
Like Salty1962 said, a Picasso is a good pairing as well. My clown in the lower right side; one side looks more like a picaso, his other side (not shown) is definitely DaVinci. He has asymmetrical markings, which I love. The other (up top) is perfectly symmetrical.
When picking up a 2nd clown, try to find one that is significantly smaller than your existing, or much larger than your existing. It will help them establish dominance without any bickering. If they are too close in size, they will fight until one submits or dies :( my 2 clowns are similar in size, and they bicker a little, but the one on top is definitely the dominant clown.