Hi!
I was wondering which are the best related mana runes (Flat Mana, Flat Mana Regen, Mana per level, Mana Regen per level) for 
(she's AD caster).
I haven't done any test yet, but I think that Mana per level and Mana Regen per level runes are the best.
The best mana runes is none of them. Because you shouldnt be using mana runes at all.
You shouldnt be spamming all your skills and going oom on any ADC.
Everyone else is going to tell you the same thing.
You don't.
MF is not an AD caster and she is intentionally mana gated, because with infinite mana she would have one of the most oppressive laning phases, because of her slow and Q.
I just ask my jungler for blue buff/ take it whenever its up, I don't take any mana related runes.
