Now guys let's all take a deep breath and relax. Safety is the key concern here.
The HNR rule is there to protect us. With several manufacturers making good HNR's and several designs to choose from, I am sure we can all find something that meets the rules and will work in our cars. (hopefully with little or no modifications to current cage or bars etc)
I know some of us may have been using nothing at all or only the old Horse Collar and anything else seems cumbersome and restrictive.... trust me I understand...
More cage, door nets, 5, 6 or 7 point seat belts, containment seats, lateral head supports and now HNR's are all there to "help" give us the best chance of walking away should the dreaded roll over, flip or tumble occur.
I am no expert (but I did stay at a Holiday Inn Express) but what I did was try on several HNR's and chose the one that fit the best and that allowed me to exit the car with the least difficulty. No one ever said exiting a race car fully suited up was going to be easy, but once you have all your gear selected, make sure you practice your bail out drill several times until you have a repeatable sequence down. Then hope you never have to put it to use.
If you really have a "specialty" set up, I am sure making a call to any of the HNR manufacturers can help, maybe they can assist... I know Safety Solutions was very helpful with my belts and HNR (a guy my size can not buy off the shelf anything, so my belts and HNR had to be custom sized... my seat too,,, Thanks ISP and Safety Solutions.)
Charles