I'd probably do Larkin, Nader, Yabusele, and Boston's 2018 1st (with some solid protections, like top 25, or it transfers to 2 2nd's) for Okafor. I don't know if the Sixers would be interested in something like that of course, but if that is the sort of deal they could get, I think it would make sense for Boston. You don't even mess up any chemistry since none of those guys were on the team last year.