I use plugs and then just push the pushrod in and out on the bench until I can't see air coming out of the ports anymore. I suppose you could do this on the car, but it's going to be a bit harder. If you did it my way, it can be like a fluid geyser coming out of the MC anyway, and you don't want that on your paint.

That looks to me like a 1 1/8" MC. I hope not, if it is, you'll have a super stiff pedal and not very responsive brakes. I highly recommend the 15/16" one from Dr. Diff or you can use the stock size 1 1/32", which will be decent as well. With the Organic pads and the 15/16 MC (and the 11.75" brakes), my car will jerk you right through the windshield without having to give it all of your might to stop.