Will the Nox have stealth capability, or have access to stealth capability in some way?

Stealth in Star Citizen is mostly about managing the emissions you make. In this regard, you will still have the same flexibility to manage your power consumption and overall signature as you will on any other ship. Additionally, you may find added benefit if you choose to replace your competition components with stealth items, but to do so would come at the cost of overall speed and performance.