I am going to a meat market where the butchers will hand cut to your specific request. What is the best weight and thickness I should ask for .
For the porterhouse I am guessing maybe 1 and 1/2 inches thick and 20 ounces in weight.
For the filet, maybe 1 inch thick and 10 ounces in size.
That's about right on the PorterHouse. Some loins are bigger, some are smaller, so it's hard to say that 1½" will equal 20 oz. But, 1½-2" is perfect for cooking and I would not order it less thick than that.
A 1" Filet will be approx 6-8 oz, maybe less. I'd go with the same thickness as the PorterHouse, 1½" and that might be closer to your desired 10 oz. Again, that would depend on the size of the Filet and which end it's cut from.
Don't let them talk you into a "Bacon Wrapped Filet", otherwise you'll be paying premium price for the bacon. Buy the bacon separate and put it on the steak yourself.
If you are in the mood for Sirloin, 2" makes a nice steak for the grill or broiler. Same with London Broil.