I need help with a new saddle!!?

I am getting a new saddle for my 15th birthday. I currently have a western saddle for my QH gelding. The one I want to get is the economy starter set at statelinetack.com I also am getting the pad but haven't decided between the Roma reversible quilted, The Elite Standard, an the Tropical Bright A/P Quilted. I am also getting a baby pad to put underneath. I know i need a 17" saddle. How do I measure for his gullet size Is the gullet in a western saddle different in an English saddle? If it helps I know that his English girth will be a 32". Yes I know he is barely able to be called a horse but he is and He loves to jump so that's what I am going to do with him. He isn't swaybacked any because I only weigh 93 pounds and he weighs almost 800. How long does it take for the average saddle to get broken in? How would You suggest I clean it/ and my current saddle where only the skirt and pommel are leather, the seat and stirrup thingees are suede!?ALSO if anybody has this saddle set already How do you like it? Would you suggest that I get a half pad to go with it or will my pad and the baby pad be fine. Thanks in advance! :) Have a great day