I also have the TST comp. box, piggybacked to the Edge EZ. While I normally run with just the injectors and the EZ, the TST is a real kick in the pants when I turn it on. Depending on what your future BOMBing needs may be, I suggest trying the Edge EZ alone first, should keep you happy for awhile. Get some gauges in that rig, at the minimum a egt (pyro) and fuel pressure gauge. If you want more than the EZ, upgrade your clutch and hog out your stock banjos with either Ray T. 's modified banjos or Weber fittings. Then try larger injectors and if they are not enough add the TST to the mix. I think you will pretty happy with the EZ alone on the ETH, going above that will require expensive mods. to the drivetrain, larger turbo for all the usable power with the big injectors and a better air filter set up ( your choice).
Which ever you choose, be sure to check your FP before any mods. , we've had too many failing lift pumps to risk the death of your injection pump. A heavy hitter like the TST comp. will tax your fuel flow with a good lift pump, so you need to keep an eye on those psi's for sure.
Forgot to add... the egt's run pretty hot on the ETH stock, adding just a set of 275 injectors will only compound the issue. If you get the EZ box, it has a boost module built in and comes with a boost elbow that you connect to the HX35. This will allow you to make more power with lower egt's than stock. Prime example, when my truck was stock with just gauges, I could hit 1300 degrees pre-turbo with very little effort on a good climb. After I installed the EZ box and boost elbow, my boost went from a stock 19 psi's at WOT to 28 psi's at WOT and the egt's never climbed above 1050 on the same climb, while going at a much faster rate. Just something else to consider. Most of the boxes out there now have a boost module built in, if you are going to try a fueling box alone on the ETH, be sure that it has that option.
Scott W.