Sport or fingering will work for the top. The top does not take a lot of yarn but I can’t really say how much. Gauge is a little hard to figure. I got about 1/2” for 3 garter ridges.
The pants take 145 yards.
The top is worked from the front hem up over the shoulders and down the back then the sides are seamed. The pants are knit in one piece from the waist in the round using dps.
I knit the same pattern with Loops and thread Woolike & #3 and it fit Piper, a Wellie sized doll.