We absolutely should not sign another young talent as a replacement for Suarez. We very much need someone who can contribute right away. We cannot babysit half the Starting XI and Messi is not getting younger either. I firmly believe we should build long-term together with competing for titles right now and that's definitely possible, but then you need a good mix of experienced players, players in their prime and young upcoming talents.
Right now we have too many older players edging towards the end of their careers or at least as starters and then we have a bunch of young talent. The only player who can be regarded as being in his prime is Coutinho and possibly Umtiti and ter Stegen if you want to add them too, although both might be 2-3 years away from that.
Barca need to sign more players that are ready to contribute heavily from Day 1. We should go for CL titles right now when we still have Messi playing like he is.
We'll be competing for CL titles after him too as long as the board and management don't royally screw up the squad and the club, but with the right system and players he's the X-factor we'll never have again so we need to go all in right now.
de Jong and de Ligt should be the only talents that we should sign. The new striker should be someone that's ready to hit big numbers right away, not someone we have to develop for another 2-3 years to get to that stage.
If Coutinho is to play as the LW in a new system with a presumably new manager we probably should make a decision on Dembele and Malcom too and keep one of them.
We might need a new RB too(again someone who can contribute right away in that position, don't ask me who though lol), and could use some funds for that as well as for MDL and FDJ.