I think the best way to get scallops is in the shell. (Of course then you have to shuck them yourself, bhut that can be fun?) At the last restaurant I spent time at, I had the pleasure of shucking 6 to 12 kg of scallops a day. They came in the back door in a wooden case.
Once opened, each scallop was full of sand. (I guess this is why they weighed so much!)
After shucking they were washed thoroughly and then drained, uncovered, in a hotel pan in the walk-in box, oftne overnight.
By the time they were used, the scallops were dry to the touch, but still shiny.
I have had bad luck in purchasing scallops marked "diver scallops", which come shipped by air from Massechusetts to California. They have been expensive and inconsistent in quality and taste. I have had better luck with one of the local Chinese supermarkets where they sell the scallops for $8.99 per pound. These never shrink or give off water when cooking. Also, they smell like scallops!