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.
If Liverpool can actually sign Isak, then they will be very strong next season. Alexander Isak will be a serious threat to the opponent's defense, and I don't think it will be long before he gels with Liverpool because he hasn't been in the Premier League for quite some time, and with Liverpool, he will be even more pampered. Now we just have to wait and see whether Liverpool will really chase Isak or if they still have other options. If Darwin Nunez is actually sold, then Liverpool will definitely be looking for a new striker.