Sounds like you need a custom roll bar.
I once read an article about a Porsche 911TT owner who had a $8,000 roll cage installed in his car because the aftermarket cages didn't fit close enough! I'm not recommending using chrome-moly or aluminum tubes, but bending some mild steel tubes to your own design should be a little less.=
I'd imagine in So Ca there should be somebody who can do the job for slightly more than a ready-made one.
I agree with the upright "staple" subtracting from the look of the car, s= o it may be worth the extra trouble.
Now about taking full liability for it's design, and integrity...
Tom Yang