Sorry I didn't get to include this before.
Door Side Harness Mount This is what I was planning on using at for the door side. It comes with all the bushings and things you need to keep the stock functioning properly.
martin's right.. Best way is to drill the floor and trans tunnel for the 6pt harnesses. Most seat mounts have a thing to mount the stock belt receiver to as well which could also be used for the tunnel side lap belt in a pinch.