Help me choose Pedals & Shoes

Stef the only place for your cleats to be is at the height of the ball of the foot, wear your shoes,
then with your finger find the part that sticks out the most on the inner side of the foot,
make a mark with a pen,
then turn the shoe around and just draw an immaginary line going straight from that mark you made directly onto the cleat, here you go.

That's not 100% true. Depending on pedaling style some people prefer the cleat located a few mm to the fore or aft of the ball-of-toe centre line.
Also, that doesn't take into account sideways angle. Stand still and look at your feet - it's usually sensible to angle the cleats to match the natural angle of your feet, ie. if you are pigeon-toed, angle your cleats out so that your shoes point slightly in, if your feet are splayed then do opposite. Basically, you don't want to be doing DD if you've not done a reasonable amount of kilometres in your shoes and corrently positioned. You will find your knees, tendons, etc in a great deal of pain if you've not set them up right.. and the cool part is.. the pain wont start until you've done 100k... ie. it's the middle of the night and you're only half way there. You've been warned!

"Thanks Mum!"