How big should my titties be?

I have some c cup breast forms before I start HRT and they’re great but idk if they’re up to a sissy standard and some guys have said they should be bigger and I agree

Ik some gals like having no titties and being flat chested but I’m more of a bimbo sissy and I wanted to fully embrace that before I grow actual tits.

What size do you think I should get girlies??

Side note:How long should my nails be as well?

Btw I present fem irl most of the time