First I don't feel comfortable making chute recommendations, I call Bob and listen to him. I will tell you what has been a problem on Hooley's car.
Hard to see, but this was our chute mount the first couple years with the roller to push the car with at the end of the bar and the attach point for the chute roller by the step-down area that is better seen in this...........................
............... picture (the chute mounts on a roller where the two taps are with holes in them). You can see the one bar held the chute, chute mount and push roller. I'm pretty sure the tube is 1 1/4 thick wall in this picture. This all worked fine for 2004 and 2005 but when Hooley tried to spin the car in 2006 and was able to catch it by getting the chute out...............
http://youtube.com/watch?v=CU59SUocJoA(a good view of the chute and how it reacted and how fast you can be sideways --- stroud chute)
................. the bar was bent at a 45 degree angle near the body. This was from the impact on the bar when the car had spun to about 90 degrees to the track and the chute hit and pulled the car back around. There is going to be a tremendous load at that time.
Since then we shorten the bar as much as possible and and doubled up on the thickness, but I still think it might have bent some last year when the same situation came up again.
I would like to see the attach point either right at the bumper area where there is a cross-member just inside or have the mount triangulated from the bumper area to where the chute attaches to the bar. If you are thinking multiple chutes at some point still just have the attach point very near to each other. The only adjustment I would consider at all is vertically if you are concerned where vertically the best attach point is. I'm doing that on my car................
http://purplesagetradingpost.com/sumner/bvillecar-2/construction%20page-101.html............................... to begin with, but it would a little harder to do with your car.
I think the idea of mounting the chute pack at an angle is a good one and has worked very well for this................
............... car that has a normal chute pack behind the doors. In fact I see no reason the pack couldn't be mounted to throw the chute at a way more vertical angle than horizontal like in the picture. They told me they have never had a deployment issue and maybe if they are on this board would like to comment. Just be careful how you route your lines so that they don't want to snag on anything as they are pulled out.
Good luck,
Sum