OS-3Bose will work, but will take a little more labor if you need any kind of VSS or Rear Signal Input wire. The OS-4 is really what you need. Especially since you should have bluetooth and the OS-3Bose will not retain your bluetooth. OS-4 will keep Bluetooth, XM, On-Star and all chimes. You can find an OS-4 on Amazon for around $100. PAC Audio sells them for around $200. Your local install shop will probably charge closer to $200.
In the end, I'd go with the OS-4. Don't forget the PAC SWI-JACK to retain all of your steering wheel controls as well. I think I saw them online for around $40-$50. The OS-4 integrates perfectly into the SWI-JACK as well.
Edit:
Didn't pay attention that you just had the OS-3, not the OS-3Bose. That won't work on a Bose system. Definitely need a new one and I'd go with the OS-4.