arrr, heel and toe, there's some car you will have a very hard time doing it. But I still think that the nsx is one of the best. Maybe it is from Japan, so my avg. asain body works fine (size 10). I never master the toe and pinky, like some said here, it depends a lot on the shoes you wear. I found it being the gas pedal a little lower than the brakes, my lugz (with relatively high heel) works fine, then on the track, a thinner sole shoes give me more direct feeling and since I brake deeper (brake pedal travel) the thinner sole also help having the correct blip.
Yes, I would say the heel and toe is kind of hard to practice, since there's not a lot of room for you to practices in street drivings. The best would be downshift at the off ramp. but I heard that you hit the track a lot, so you should keep practicing. On track braking, you just try to memarize that instead of putting your whole foot on the brake pedal vetically (naturally), Forget the whole Heel and toe deal, here you approaching braking point, left foot cluth in, right foot put horizontally and instead of aiming your foot to the middle of the pedal, you are trying to offset it, so your shoe will press both pedals down at the same time. Downshift hand movement should be at the same timing as the left foot clutch....
it's kind of weird for someone like me without whole lot of track experiences giving driving advise to veteran racer... Don't rush yourself, keep practicing and you will pick up one time, then you will never forget. (it takes practice when you jump from one car to the other even after you master the skill.)
oh, on car equipment part, if you want to dedicate just to "get" the skill, put stock or softer pads or even a more wear pads, since both will increase the brake pedal travel relatively to the gas pedal. Good LUCK.!!