I'd go with the K at the top and the T below that - because, generally, you can mount the pole on the K alone and then position the T to correct any side-side "non-verticality" in it, and the slots in the T to correct any front-to-back "non-verticality" in it.
Edited: & here's another thought: if the dish is above the top bracket then most of the wind-loading will be on that top bracket - so that is where you need the strongest attachment to the wall, and that will be the K bracket as it more fixings than the T-bracket.