HiAnnabannana
I had a bilateral mastectomy, so can’t advise you regarding one implant, one natural.
But generally, my implants are heavier than natural breasts and more firm. The weight took a bit of getting used to. Maybe ask your surgeon or breast cancer nurse (or a friend) if they have an implant you can feel?
Because the mastectomy removes most of the breast tissue, you can clearly tell I have implants when I am naked - they are up front and round. I also have some slight rippling if my posture is bad (shoulders rounded). With clothes or bathers on, I think they look good.
I have two angled scars where my nipples were removed (that look like \ & /) so I can wear low v-neck clothes if I want to. The scars are fading, but will probably always be visible (although a nipple tattoo would cover most of the scar).
You could join the private reconstruction group on here and someone who has done one of each might be able to help further. Otherwise, feel free to throw some questions my way.