You're limited to the apps and versions you can install by virtue of your 8310 running OS 4.5 only. The version of BBM you can run is dependent on the device itself and the OS version. The 8310 is still a very serviceable BlackBerry, but it's not going to see any new development. You can grab
OS 4.5.0.313, the latest version of the BlackBerry OS available and see if that brings any new capabilities as far as BBM, but things like UberSocial are only for later versions of the OS. Check out App World to see what's available as far as Twitter goes. App World should take into account your device/OS to show you what's available to you. I'm sorry to say it, but there might not be much for such an old device as the 8310.