While there are a lot of options, we suggest you consider the following when purchasing a package to populate your new hive:
Local: If you live in an area where there are package suppliers, seek them out first to see if they would be a suitable option. This will minimize the environmental impact of trucking them across the country, as well as provide you with bees that may be better acclimated to your area.
Hygienic: You want bees that are survivors...that is bees that can survive without human intervention with chemicals and treatments. In today's world of Varroa mites, small hive beetles, Nosema, IAPV and other problems, your bees will have the best possible chance if they can take care of themselves. Bees that are genetically disposed to groom themselves and the rest of the hive of mites will have a significant advantage over bees that aren't.
Treatment Free: Determine whether the package supplier is treatment free. While it's not likely that they are, it's a good question to ask. If they do use treatments, learn what treatments they are using and which chemicals are involved, if any. Most top bar hive and Warre hive beekeepers do not treat their hives using any chemicals, and to cut off a colony cold turkey from chemicals upon which they've been relying for years could seal their doom.
Buy Early: Packages can be hard to come by unless you order early. Most suppliers require a 50% deposit fee, and I recommend that you get your order in by January at the latest to ensure there will still be packages in stock.