Verratti is a player I covet strongly for Barca. Such a talented young player. Anything the team can do to secure him, they should move heaven and earth to do it, however difficult it might be.
Gundogan's situation, with his recuperation and contract, might also present a nice target for a verbal commitment and leave him playing in Dortmund one more season as he regains his form. He's also likely to not cost an extravagant amount.
Barca needs to plan their transfers and reinforcements starting now, hence getting a new, and good, Sporting Director quickly is a very important task. By summer 2016 the team is likely to need 2 CMs (again) with Iniesta 32 and Rakitic 28. Rafinha might not develop to the level needed, ditto with Roberto, and Denis Suarez looks more offensive minded. Planning and setting up the groundwork for then is key.
Likely to need 2 RBs as well, another LB, a CB too.