For 8" tosai, my concern would be that it is nearly July, so not much time left to get her to 20" before winter.
Seriously, I'd not worry about the Sumi at that size. It is too soon to know what it might do. Photo angle causes some fore-shortening, I think. So, what I'm focusing on is the breadth of the shoulder area. Pattern is classic ... never a bad bet to go with traditional step pattern with nice odome! If the parentage is known, I would not expect it to be for sale. But, this is a peculiar time in Japan. Still, I'd expect a fairly high price for so young a fish.