Lewis, Jody (jbc3) did an EXCELLENT 6 point drag style cage. It has a rear hoop for the roofline protection, and ties into the firewall down at the rockerpanel level. There is no front Hoop to hit your head on. That's what you want. But I'd go to a shop that does cages and get them to work with you on a custom cage. You'll have around $1500-2500 in the right cage, but it will fit your needs. Also, these rollcage kits being offered by Jegs and S&W use tubing that is larger than you need, and isn't always DOM, which is the type of tubing you want. You only need 1.5inch DOM .120 thick tubing for a cage in that car...
Also, Beware that 4 point or 5 piont harnesses aren't DOT approved with good reason. The webbing isn't UV safe and will degrade with time. 4 and 5 point harnesses also only work with proper seat selection. You should have harness belt pass thru ports in order for the harness to do its job properly. They're also a real pain in the but in a daily driver. I think newer versions of the OEM belts would be a better solution if you can retrofit some from another model year vehicle for daily use.
Mike