The person I have dealt with there (ccritters) is Dana. Nice lady. However, the ones I received were very small and did not have a lot of color. I see she has some more colors now listed on her website, but they do not look impressive compared to other sites (maybe she just needs to spice up her webpage with better pics) However, her shipping rates are very fair.
Getting one with 4-5 different colors already on one rock is a tall order. You will most likely have to create your own.
I have found that once they have at least a small shell or something attached I have about a 90% successful attachment rate. You have to use the "gell" superglue. Easy to do unless they are not attached to something. You should not try to glue them directly to anything (not that you said you did).
I have also seen some good deals on ebay, but the shipping is usually high, especially if you are just buying a couple. However, they usually combine orders for a flat shipping fee so splitting it would make it much better. Jason and I bought some (seperately) from a guy that I think was in Portland and the colors were fantastic.
The challenge will be finding the rics we both want at the same vendor.
I will PM you in a bit.....