For a 5k OCI, use Napa Synthetic, which is on sale for $2.99 this month. It's rebranded Synpower. While you're there, pick up a Napa Silver or Proselect filter. The gold is top quality, but no need to spend the extra money if you don't want to.
For a longer OCI, but don't go beyond 10k, my pick is Castrol Edge 0w30, but Pennzoil Platinum 5w30 is also a great oil. Pair it with Fram Ultra, Wix XP, Napa Platinum, CQ Blue, or Mobil 1.