New Build Question - Raspberry Pi3 + Navio2

I’m hoping this is the right area to ask this question, if not feel free to move it.

I’m looking at building my first drone and need some suggestions on what parts to buy. I would like to keep it a small/medium build (if possible). It will be primarily for video recording my son.

Things that I already own:
Raspberry Pi3
Navio2
GoPro Hero 4

Thanks in advance!

I would go with an F550 frame hexacopter, to deal with a motor failure if it happens…but you can also go with a quad F450…both very cheap, popular…parts to buy? I think if you are asking that you need to do a lot more learning about multirotors to be honest…try reading around the arducopter site, tons of useful info and also try rcgroups.com