All that OKC needs to do to match the incoming salary of Lopez is to add Grant Jerrett to the deal. I think that's what they'd like to do.
They're hard-capped, so I think they'll want to (or need to) shed a little more salary than Jerrett. I expect Morrow to the Nets.
We could save the Nets tens of millions of luxury tax if we took Perk. Not sure that the Nets would do such a thing, because they've invested a lot in being competitive, but they have an opportunity to save tons of dollars right now if they give someone a 2020 1st round pick.m
Edit: if they did send Perk to Boston (or Philly), they could use the Kirilenko exception on Lamb (or Morrow if my guess is right) and get a huge exception for most or all of Lopez's salary this year.