Marker 3: 3 Seed Bombers (Green Arrow), a Pylon, Mushroom and Golem
Marker 4: You'll have 5 DU spare, this leaves options. A gas trap, darkness trap or another 4DU buff beam (Place this with the auras), But this is not necessary and is completely optional.
Use a TB to speed up the run, I also upgrade but I dont think it is needed if your stats are high.