I am one of the old brigade I'm afraid I still believe in planting out Oct/Nov.
Regarding variety and I am only guessing or kidding myself! but I find saving my own is best, certainly more reliable!
Many years ago I bought a couple of bulbs of 'Tesc*'s finest' and planted out only the biggest cloves (I ate the small ones).
OK that first year these returned a bit of a mixed bag but what I did was; I saved two/three of the biggest bulbs I grew for planting out the following year.
Again! as always, I only planted the largest cloves. (planting small ones is a waste of time in my opinion)
Now I think (the guessing/kidding bit

) I have garlic stock that is suited to my growing methods and soil.
I will continue using this method and stock until I see a marked reduction in quality in my harvest then I will start again with another batch of supermarket quality bulbs.
In fact later this year I will be filtering in one new white bulb (my others were purple) I found in the pile from the supermarket to see how it goes on!
What was the deciding factor I hear you ask for going this route?
The cost!! i.e. about 30-40p per bulb against £1-50+ for stuff that won't necessarily give you better results ( although you would like to think it should)