Rearsets

Hello,
I want to make some rearset footpegs for my bantam project. I have some alluminium sheet for this. My question is, how do I go about positioning the pegs? Are there any designs available, especially for the brake lever?
I'll attach the plates where the usual rear footrest plates go, and have filed out the front profile for this, but I'm unsure as to how far to go.
BTW, I'm nearly 6ft tall, so any advice on how not to put my back out would be useful too! I'm not making a proper racer for events, just a bike for the road that is a bit out of the ordinary.
Thanks
Phill