I would go with Strome.
- Panarin does not have chemistry with anybody. He possibly could make 80 pts with anybody, but not 100+. That is a large difference. Columbus had no fit and Panarin had 80+ points... BTW they tried to play with Mika, other guys. No big chemistry found. So, actually we pay Strome's price and get Strome's natural points + ~20 extra points because of Panarin. I think that is a good deal.
- Strome has a fast thinking brain what is a must to play with Panarin. And Panarin is playing with Strome, not carrying him.
- with Strome you can play further with the line as he is versatile - Panarin loves unexpected ways to play and you need to be versatile here.
- Strome's points without Panarin makes no sense, because all the team has different numbers without him. And he plays with Panarin for the next 6+ years...
- Kreider and Fast both are 28. That is too much for the rebuilding team if you are not a superstar. They are both good players, but we have Panarin and these 20+ extra points.