Rather than going off your friend's saddle size, which may or may not be a 16", and fit will depend on a lot of things, try using the following links to get a good starting point to estimate your seat size. Remember that English saddle seat sizes don't so much go off the size of your butt as the length of your femur. English Saddle Seat Size Calculator Saddle Sizing Info
Look through this thread about tree sizes as well. A question about measuring
What discipline will you be riding: general backing, pleasure, dressage, some jumping? Do you like a flat seat or a deep seat? Do you like having no knee pad or knee blocks (close contact saddle) or do you like some support at the knees?
Once you know your seat size, tree width, and style you like, then start looking.
The Crosby PdN is a respectable saddle. It has a flat seat and no knee support. Good A/P saddle.
In your last post, saddles 1 and 3 are jumping saddles. Saddle 2 looks A/P. All 3 of those are going to give your more support and probably more cushioning than the older Crosby.