Pick one for each hero. Exact numbers might not be completely balanced.
Ana:
Nano cost increased by 20 %.
Nano healing decreased to 200 hp (currently 300 hp).
Nade buff/debuff duration decreased to 3 s (currently 4 s).
Brigitte:
Inspire healing decreased to 15 hps (currently 16 hps).
Inspire radius lowered to 18 m (currently 20 m).
Inspire duration lowered to 4 s (currently 5 s).
Melee damage decreased to 30 damage/swing (currently 35 damage/swing) and Whip Shot damage increased to 75 damage (currently 70 damage) (keeping the burst combo the same, dropping Brigitte's overall dps slightly (one extra attack would be needed to kill a 200 hp hero with basic attacks alone), slightly increasing Brigitte's ranged damage).
Whip Shot cooldown increased to 5 s (currently 4 s).
Repair Pack overheal decreased to 50 armour (currently 75 armour).
Repair Pack cooldown increased to 7 s (currently 6 s).
Rally cost increased by 10 %.
Lúcio:
No idea.
Mercy:*
I've not tried the PTR version (with buffed Valk charge rate and Valk healing), so I can't comment on that one.
Non-Valk healing increased to 55 hps (currently 50 hps) (with Valk either being 60 hps (PTR buff) or 55 hps), with ult charge adjusted accordingly to keep charge rate the same as pre-August nerf.
Rez cast time decreased to 1.5 s (currently 1.75 s).
Rez cooldown decreased to 25 s (currently 30 s).
Moira:
Biotic Grasp max range decreased to 20 m (currently 21 m).
Biotic Orb's cooldown increased to 12 s (currently 10 s).
Biotic Grasp's HoT lowered to 50 hp over 4 s (currently 50 hp over 3 s).
Biotic Grasp's HoT lowered to 40 hp over 3 s (currently 50 hp over 3 s).
Healing resource passive recharge rate lowered by 8.8 % (effectively making the August buff 10 % rather than 20 %).
Zenyatta:
No idea.
As for new Support ideas, I wrote down a bunch of ideas a few months ago.