I'd also stay away from Chiesa. He's right footed Berna - fast dude with little end product that needs space to operate. Both are actually good fits for wingers in 442 or wingbacks in 352. Just run a lot, help your friends and produce an assist or goal once every few games (when in form).
If we assume that Kulu replaces DC, then Berna's replacement should be Zaniolo. If we can't afford Zaniolo now, start to save up money for next year. We need to buy good fits instead of choosing out of what is available in the market.
I don’t get the comparison with Berna. Chiesa is more a classical winger, indeed uses a lot of speed, but cross way more, is more dynamic and shoots often. Berna, Kulu, Zaniolo, Ilicic, etc are all very different from him; more physical, technical, less width, left footed, they all have a very different profile than Chiesa has, with Berna obviously the least of them.
I’ve seen games at Italy U21 for example where Chiesa was carrying the team as LW and Zaniolo failed to impress as RW.
If I could choose I’d also choose Zaniolo, but the comparison with Berna isn’t right. From a tactical point of view Chiesa offers something very different compared to Kulusevski or Zaniolo.
If signing Zaniolo becomes impossible I’d be very happy to add Kulu to the midfield and sign Chiesa as a RW, for the right prize of course.