Cheryl, there is a lot more to sporran positioning than looks.

Function (what is the sporran supposed to do), how much it has to move around (drummers have then on their hips) and finally anatomy (boys and girls are different).

Final height is up to you. You have to be able to use it and it mustn't get in your way when you are working.

I would recommend a strap rather than a chain. The sporran will slide on a strap, whereas the sporran and straps have to move together. Loops will always show (no matter how well they are made), so you might as well have a pair made from a solid colour or even leather.

As far as I am concerned, your outfit looks OK as it is.

Regards

Chas