The profile is the width or the implant and also how far the implant protrudes/projects/sticks out from your chest wall. Generally speaking high/xhp would be used for a faker look all though it more depeands on your body anatomy, cc ect. It also goes by your BWD, base width diameter, this is how much room there is in your chest for the implant, if your BWD is very wide, you will need to have low/moderate implants for the implant to be wide enough for you or you will have a very large gap. if you’re narrow you will need a higher profile so that they don’t meet in the middle and cause a complication called symastia. This may help : noobiestoboobies.blogspot.ie/2013/10/breast-implant-catalouges-sizing-info.html
The natural fake look depends on your body more than anything, I have 615cc round, xhp, overs, they don;t much faker than that lol yet I still have a natural looking result. Hope this helps x