Hey Pregan59,
Congrats on the rig and future GW. Most 347 I am aware of come with D-rings (4) recessed in the floor. See if my measurements are the same as yours. If you don't have D-rings or if you want to add E strips, do some investigation on maximizing the secure points. Look at 3/17/2010 in this thread by Mainier. There are several posts in this thread about what some of us have done or plan on doing to secure our rides. Check them out and see what questions come to mind.
Some really good points on the ramp, too. I don't have my trailer yet, so it will be a new experience for me. I have loaded bikes in and out of my pu numerous times. The key is to have the break over to a minimum at the top of the ramp so there is clearance.
Good luck.