Well, codeallen, you are going to have the same problem, only worse with the iPhone 5. It will most likely come with iOS 7, which requires iTunes 11. With the 4 you can stop upgrading the iOS at 10.6.8 and iTunes 10.7. If you hurry you can still download iTunes 10.7, before they remove it, is still available at Apple Support. As I understand it, it is the only other version, besides 10.6.3 for PPC Macs, that is available, other than the current version.
I believe OS X 10.6 is available for $29.
With 10.6.8, you still have Rosetta, and do not need to replace several pieces of your other software. With 10.7, you will most likely need to upgrade other 3rd party software. So if you need to update MS Office, figure at least $100 to $200, more.
You have a choice, stick to your guns about not updating your OS some, and have 2 iPhones you can not sync, or upgrade to OS X 10.6, and spend only about $29. Your choice, we just don't want to hear any whining. We're trying to give you a complete picture of what to expect, which you apparently did not do when you updated the iPhone 4 to 11.1.