Noon Eastern, I would go 5K, half, and then Dopey (the shorter distances tend to sell out sooner). There are some that say you will need an active.com account for both but I think I was able to register my whole family on my account (it asks if you are registering for yourself or someone else on one of the first couple screens). I would have your CC info and proof of time info (Race name, date, time, race website) typed out in a Word document so you can just copy and paste that info into the form to speed things up.
Edit: In my original response I did not factor in the cancelled half this year but that only strengthens my opinion on going with the 5k, Half, and Dopey in that order.