Hostas

Is it possible to get large, healthy hostas like this now? 

If the deer don't eat them, it's possible.  Hosta are easy to grow and to transplant.  They are also the favorite food of deer, a veritable salad bar for the antlered rats. If you have deer in your area, you need to get a good deer repellent, and spray the hosta almost every day from the time you see the first shoots until the first frost.

great! Where can I buy them?

It's going to be very hard to purchase nice looking hosta plants this time of the year. I will be pulling Hostas to divide next spring (March or early April) when they are first breaking ground. If you can wait until then, I'll have lots to give away. 

They're also tasty early in the season (at least my solid greens are).

Mine are starting to decline at this time of the season.