Sammy Watkins and Donte Moncrief are probably the two most obvious names, given the connection with Lal. Of those, only Watkins is a legitimate replacement for Dez and is still a step down at that. Though he does give us the speed we're looking to add offensively.
Moncrief or a draft pick, or both, to replace Butler. Let them compete with Noah Brown for snaps. Dez' red zone looks maybe got to a player like Gathers if he makes the roster, more passes to Elliott, and continue the option keepers that Dak's good with.
It probably ends up being more expensive than keeping or extending Dez, but we get younger and more explosive with it, and the players all have ties to the staff.