VANOS - Uh Oh?

[4.6toddy]

Last week I heard the supercharger sounding whining noise coming from my X 4.6IS. 2 or 3 days later, it ran rough, followed by check engine light the next day. I pulled the codes and have several misfire codes and two VANOS codes.

I've searched the threads on here, all seems to be pointing towards failure of the VANOS or the chain tensioner?!

Had it flatbedded to the Local Euro Indy for diagnosis Monday. What should I be wary of? While it's in there, is there anything else that should be changed?

Am I likely looking at just replacing the timing chain tensioner which from what I read will tighten up the chain and bring everything back as should be or am I staring in the face of changing both VANOS completely?