Fear is setting in that this is just a dumb dream. Just make it a fun car, then build/buy a ready built chassis and have it dedicated to this plan. This is plan B, and may be too late to make it good/safe enough at this point.
If you just want to go fast, have you looked at something like Silver State Challenge?
It's a timed road event and they got classes that can go over 200 mph, but most of the lower classes need a roll bar at best, and the top 2 classes need a cage. So you can work your way up through the classes as you can afford it, I've always wanted to someday run it myself.
