My first thought is exactly what luvs2ride said. The seat of your saddle is too small for your body (i've always been taught you should have a hand's width behind your butt) and that the bottom of the flap of your saddle hits too far down on your leg, which means it's too long. The bottom edge should hit higher up on your calf.
HOWEVER- the more I look at your picture the more I think the size MAY not be as far off. I think it looks improperly sized due to your position. (perhaps your position is off because of your saddle?). You're sitting far back in the seat (Where you should be closer to the pommel) which makes the seat look smaller then it is, esp since you're resting your hands on the pommel. Makes it harder to see how much saddle is in front of you. And with your leg out in front of you, where your heel should be directly in line with your hip. That will give you a shorter leg as well. While there's a good chance you'll need a larger size with a short flap, the degree of how much will be harder to tell without a more correct position. If you take a picture from the side of you sitting in the middle of the seat and just let your leg dangle down it's easier to see where the flap is in relation to your leg. Another major issue is that your flap is set very forward, too far forward then what you need. Unless you ride with a very short stirrup your knee will not touch the knee roll. But regardless, I do think you need a new saddle. These are the kind of saddles that I usually warn people away from, they do not encourage proper position! Pretty much any saddle you listed is a better brand then what you're sitting in now. Always get the best quality your wallet can afford (heck, you can swing a CWD go for it!).