Liverpool has't stopped yet. They're trying to hunt more talent to be recruited. They have done with Frimpong, Wirtz (medical check up), Kerkez, (still in the negotiation), and add Isaak as their last target. Their target to sign Isaak from Newcastle is just getting even more possible with Nunez who is still in the process to go to the Napoli(i expect him to play for that italian club).
I think we will see Isaak to wear Liverpool's jersey as he has open the move to the any big club that play in UCL.
It would be great for Nunez to join Napoli, it would even remind us a bit of his fellow countryman Edinson Cavani. Isak is an excellent player who i believe would fit in really well with Liverpool's squad, and i think he could be a serious reinforcement especially since, as you mentioned, he's open to joining a bigger club that plays in the champions league.As for Kerkez, i think that deal is pretty much done, at least based on what i've read. But let's wait and see what might still happen with that transfer.
About Nunez I can't why he could not perform really well but leaving Liverpool to Napoli is good at least he can be a regular starter and he can as well be better than we saw at Liverpool. I believe Isak can fit in any team in the EPL and his form since he joined Newcastle has been awesome and you can agree with me that he is one of the best attackers last season. He is not as macho as some attackers are but he can pass through every defender. In my opinion I would not like Newcastle to be useless next season for letting one of their best go, so who's going to be his replacement for next season? For me is bad and I know their attacking force will never be the same if Isak leaves.
Definitely, if Nunez moves to Napoli, he has something to prove. Let’s not kid ourselves the premier league demands more than the Italian league. I do follow serie a and it’s a strong league, but the premier league is still the best in the world. In general, Nunez is not always consistent his performances fluctuate, sometimes he's good, sometimes not. Maybe Liverpool is just too big of a challenge for him right now. If he joins Napoli, he and Lukaku could form an ideal attacking duo.As for Isak he’s a top class striker. He knows how to read the game and has a great sense for goal. It’ll be tough for Newcastle to find another striker as good as him. Liverpool is doing a great job preparing for next season, and i believe they’ll be the main favorites to win both the league and the Champions League.