This one is pretty popular from what I'm reading:
http://www.greendieselengineering.com/PerfCompFCAEcoDiesel.action
PPEI Tuning will be offering a ECM swap for true custom tuning, which will be hard to be.
You can buy a Banks Bullet, or TS MP8.. but I would hold out for the true tuning.. if...
The overall word is, "No". But I'm not 100% sure, I know most lift and leveling kits are made for the trucks without the air suspension. Maybe someone else here can chime in
I didn't know about the money back deal..
When I purchased my Jetta TDI, I bought an extended warranty, and of course never used it. That has turned me off since from buying them..
Welcome @Jambrose711 .
You're the typical truck owner, we're always wanting more power and better tires! :D
Be sure to ask any questions, the guys here would love to help out any way.
As far as tuning, good tuning that will REALLY make a difference will probably void your powertrain warranty...