I always liked IWB at about 4:00, but you may find your comfort zone is elsewhere. Best thing is go to a LGS and ask them if you can bring in your gun to try some different holsters with it to see what is comfortable.
You may consider a shoulder rig, because 15rnds of .45 isn't on the list of things I refer to as light. Personally, I would open carry if it is legal in your state.
