x2 on Jeffers! I order almost everything from them...it always comes packaged *very* well, and shipment is quite fast. They are also extremely helpful and go above and beyond when you send an e-mail with questions; a very knowledgeable staff, too. They even sent me an e-mail when I placed an order for a few antibiotics, just to tell me that two of the antibiotics were similar in nature, just different names, and asked if I was sure I wanted both of them. When I explained that I was a noob they went over ALL of them with me, helped me plan my order AND immediately reimbursed me for the items I ended up not getting. They're now my "go to" for chick(en) supplies.
In regard to the Corid - I REALLY LIKE how Jeffers has the little tiny 16 ounce bottle of it for those of us who have a tiny flock. =)