3.1.3 was your first mistake...
Second, you don't need to jailbreak in order to have more than 144 apps. Your iPhone/iTouch can handle more than that, just that you won't see the icons. However, if you swipe to the left from your home screen and search for the app you want, you will find it.
However, once 3.1.3 can be jailbroken, you can always get "Categories".