I've had a look through the wiring diagrams for the Vibe and from what I see, they are different enough configurations that I don't see it being a very good option.
It doesn't look as though the Vibe radio supports steering wheel controls. There is a version which has a separate audio amp, but not with the nav option. The Monsoon amp will not be compatible with the Vibe HU for numerous reasons. I'm also not convinced the Bonneville antenna module is controlled the same as in the Vibe. There are some big compatibility issues here. If you want OEM appearance, there is a TNR800 which I know will work (being that you have Monsoon). It is your best option "for OEM likeness" with the most compatibility to existing vehicle systems (steering wheel controls, XM, CD changer, OnStar, etc).
If you haven't seen this thread already, look here:
You can also consider aftermarket, but this isn't without issues as well. To maintain your chimes, OnStar and steering wheel controls, etc. you will need to add additional modules to take over these functions.