Android 4.3 Touchwiz rom is now available for you to play with on your T-Mobile Samsung Galaxy S4. This rom has been built for the leaked I9505XXUEMI8 Android 4.3 build for the International Galaxy S4. The rom is deodexed and Knox has been removed. A few things like wifi and NFC payments do not work hence it may not be a daily driver yet but we hope those are fixed soon.
Installation is as simple as flashing a file from recovery, once installed you can root using Chainfire’s 4.3 root. For more details and download links head over to the original thread at xda.