I also got caught "late" with my Pepper seedlings last year. This time around, I started the Peppers on Dec 6, and the tomatoes 30 days later. Seems to have been a good plan. All of the seedlings look to be the same height today.
This year I'm growing:
Big Bertha
Colossal
Early Thickset
Parks Yellow
Parks Orange
Parks Purple
NuMex Big Jim
NuMex Joe Parker
Last year, I planted 6 Pepper plants per EarthTainer which turned out to be far too crowded:
Now, I will plant 4 Peppers per 'Tainer max and I think the size of the individual Peppers will be larger, given some elbow room to develop.
Raybo