You don't have to spend a fortune and it isnt all that hard. We can help get you straight and help find something suitable that will make you happy. Post some good plain side shots and a front shot of your horse, and let us know what you want to do with the horse. Then we can help you in the right path. Saddles are expensive and all of us have bought wrong saddles before.
But basic rule is , saddles should fit, pads are for padding. You don't use a pad to get a saddle to fit. Now if you already have a saddle and just wanna get buy, sure go for a bit of pad adjustment. But anyone that tells you right off the bat to use different padding to make a saddle you want to buy fit is taking advantage of you or doesnt know what they are talking about and just trying to make a sale. Horsesaddleshop.com has some pretty decent templates you can download, print and then put on cardboard and cut out.