Temperature is always going to be how you want your steak, so 53C good.
You need at least an hour in the tub to reach thermal equalibrium, but can go for 2 hours with no issues. I'm guessing by the Richmond Tigers and Celsius temps we're talking Aussie porterhouse which is NY strip to our American friends. Good steak, but not as tender as scotch (boned ribeye) so your steak, although thin, will benefit from extra tub time.
Being so thin you are going to need to be careful when searing so as not to push it beyond the perfection that comes out of the cooking bath. If you give it a short dunk in some icewater before you take it out of the bag you will give yourself a bit of wriggle room. Dry it very well. Salt and pepper and place in a very hot, lightly oiled pan. 20-30 seconds max and flip.... another 20-30 secs before serving on a preheated plate.