about 20 are first early so I should get something
If I can make a suggestion re-quantities!
May I suggest you go for 1st & 2nd earlies and maincrop and this will give you an extended growing season.
I tend to go for 25% 1st Early (Either Rocket or Foremost) Then I go for an early 2nd Early (if that makes sense) I tend to use Charlotte, the next 25% is a late 2nd Early such as Kestrel. The final 25% I grow Pink Fir Apple.
What I find with this method is I do not get a glut, I always get that "just picked" taste due to lifting them as I need them and I am eating freshly picked potatoes from early July until the frosts and the maincrop well into the following spring.
As I said this is only a suggestion from a GOM