How does iPhone 2G download apps?

So, I have to choose between an iPhone 3GS or iPhone 2G (I like the vintage feel of the 2G) but the one deciding factor may be that most apps are compatible with the 3GS not the 2G! So my question is, if you download an app from iTunes, then sync it with a 2G does it just download an older compatible version of the app or do you need to get the latest? Is there any way to get an older version?

Download the latest update for iOS and update your phone. Then go on wi-fi and download whatever you can. And the original iPhone isn't vintage. That'd mean the Xbox 360 is vintage.

The 3GS of course is the better phone here. Getting a 2G or 3G at this point makes no sense. The 2G & 3G support up to iOS 3.1.3 & 4.2.1 respectively but most apps require iOS 4.3 to run.

So long story short, get the 3GS which can run up to iOS 6.0.1 which is the latest so all apps will be able to run on it.