I'm currently running a project on Virgo GXs, distances are a topic, too. According to my sources NGC4216 has a (non-redshift) Tully-Fisher distance of 16.07Mpc, distance modulus of m-M=31.01 (+-20% errors in distance, +-0.4mag in mags). Maybe you re-calculate your SN estimates ...
NGCs 4278/83/86 are in the same field. 4 NGC # Messier # RA 4414 4449 4472 4490 4486 4494 4501 4517 4526 4535 4548 4552 4559 4565 4567/8 4569 4579 4605 4594 4621 4631 4649 4656/7 4699 4725 4736 4762 4826 5005 5033 5055 5194/5 5236 5457 5746 5907 6503 M49 M87 M88 M91 M89 ...