I've been looking into this more too. I really like Racetech seats from the second post, the RT4009W, which is 590mm wide at the shoulder wings which
Focusedintntions says have about 2mm to the door card in his install thread (
https://www.1addicts.com/forums/showthread.php?t=791693). So it seems like that is a good limit to seat width for the E82, which is a shame because the new Racetech RT4100 is even wider at the shoulders.
Without the door panels you'll have way more room. Sparco lists the PRO ADV at 630mm so 20mm of that would stick past the door card location roughly. It also can depend on how close you can mount the seat to the transmission tunnel.