Ryan Casserly injectors from Full Force Diesel are great rebuilds. Each injector is fully tested before it leaves the shop. You can get them from caryt here on the forum or from DP-Tuner. I think caryt can help you with programming changes for your TS that you will need if you decide to go with the stage 1 single shots. PM him - he will get you set up.
I think he has the parts for the Garrett as well. Here's a link to the Full Force Diesel website: