I have to agree with Vanning, his post is spot on...
The Team Durango plastics are exactly the same as Arrma's, and I highly doubt the shock shafts are any different. They might have a coating on them, but that won't prevent them from bending. A relatively cheap way to find out it's to just replaced your Arrma shafts with Durango, they should fit, but you'll want to verify that for yourself.
As Vanning said, the strength you're seeking comes from thicker shafts.