If the cross planet wave goes straight for your command center I may have to recommend this.Helms Deep
You could try that, although it was designed for before 4.0, but I have been using with great success still.
I only recommend 50 or less spider and sniper turrets for each.
You should be able to get away with no trader items like I have.
I got away with my first CPA by doing my helms deep, then placing additional turrets at the wormhole.
The wormhole turrets being mainly MK1 gravity turrets and lightings.
I haven't tried this yet but how about making a ring of forcefields around the wormhole so the ships are contained in a small perimeter.