IMO, leg support is an important often overlooked feature in a race seat. most street "race" seats have none, only the real stuff does (because it makes getting in/out of the car a PITA). with proper leg support, you have MUCH more control over throttle/braking while turning. esp throttle.. which kinda matters when you have power. you may be ok with NA 13b.
example-
Sparco Evo, not a race seat. These are horribly popular for some reason, and dont support you where it counts.
Cobra Suzuka, race seat. your knees wont go anywhere. Same with racetech/kirkey/sparco corsa/etc.
ok that is all lol. not trying to rain on your parade, its just something people dont think about until they've driven a proper seat.