I'll be interested to see if there is a preference... I don't know the pros or cons of any particular planting method combined with light dep.
Personally, I'm going to do mine in the ground. As a side benefit, it will keep the hoop tunnel as low as possible. I've tried different kinds of pots and such, and nothing seems to compare to digging a big hole in the ground and filling it with a good soil blend and dropping them right in. At least in my yard, with my local soil, in my climate... that's whats worked for me.