A trade in 2 parts...
76ers trade the #3 with PG contract, along with the Gordon/Drummond opt-ins. In return, they get Vassel, an expiring Harrison Barnes, the #14, 2027 ATL #1, and 3 future 2nds that are not San Antonio's. Shave 14 million in cap this year and, with Vassell is on a declining contract, he makes 1/2 as much as PG next year (27 to 54), and the gap is higher in year 3.
San Antonio would keep their #2 in the above, but turn and trade the #3, the #38, a future 2nd, and Keldon Johnson (along with Drummond as a backup C) to NOP, who have been trying to move up for Edgecombe. In return, Troy Murphy comes back, along with the #7.
Spurs move from #14 to #7, give up a future ATL first and a few 2nds, and walk into next year with Fox / Castle / Wemby / Troy Murphy / PG3 as a starting 5, add a year of Gordon & the #2 (Harper) and #7 picks in this year's draft, and move firmly into Title Talk Town. Even with PG's contract, they're 27 mil under the cap, and won't hit apron issues until the first year of Wemby's extension / last year of PG's contract.