I'm definitely with Barb and Matt on this one. No loops are needed for a sporran. As a general rule I don't put loops on kilts I make for myself, nor do I need to have a third buckle if the fabric is heavy enough. When I look over the history of kilts, I don’t see belts being very common at all. While I’ve not adopted Matt’s solution to the hole in the kilt, I have reinforced the button hole with light leather and sewn it done.
I retro-fitted one of my kilts with the belt that goes all the way around the back and only attaches to the buckle on the upper apron. I did put loops on for that one, but I'm still debating if I should continue with that practice. Any comments or experience will be appreciated.