What size pot to start Autos in??

So I have the jiffy pots and the jiffy pellets and some 3x3 starter pots. The jiffy pellets work fine for 1-3weeks, they just seem to stretch out the plant a bit more than necessary, the jiffy pots are decent, good for a few weeks and the starter pots are what your actully supposed to start plants in but do you think that autoflowering strains would like to be rootbound before being transplanted into the ground? I am only going to transplant one time, from the pot they start in straight to the ground. so yeah. help me out, thanks.

I start my autos where ever they are going to finish. No transplanting, No stress, Bigger yeildzs.3 gallon pots.

Just planted mine into 3 gallons with no intention of moving them. With that short life cycle you don't want to waste any time recovering from transplant stress/damage.

i live in alaska and starting plants outside is out of the question. so jiffy pellets?