oscars are pretty peaceful man, so are chocolate cichlids and blood parrots
I find the thing with cichlids is that you'd want a balance of power between cichlids...a single cichlid of any kind might become a bully but have like 6 individuals and the aggression is spread between them and creates a steady balance of power.
Geos are nice, super nice in fact, you could probably just do all geophagus and be fine. I wouldn't do an oscar with ropes though, just out of fear of the oscar thinking the rope is a worm and trying to eat it. Bichirs aren't all that aggressive, I have them in my tank, but you gotta get the smaller species like delheizi and senegalensis, they stay under a foot long generally and have smaller mouths, meaning they will eat less.
I think, btw, that the eel with plants won't end well just cause most eels like to dig. So that is something worth potentially noting. The african leaf fish (ctnepoma) are super slow growers btw, so its something you'd want to grow out or get first. They are nice looking fish though, and pretty passive in general. If doing pleco's, can't go wrong with some bristle nose pleco varieties....medusa's are larger, rarer, and pretty sweet looking if you can find them.
Festivums are nice...maybe you would want to do a thing like a pair of festivum and a pair of geophagus and then a pair or single of a larger cichlid like a chocolate or something? AN oscar will probably be a digger on second thought so maybe avoid it...or just do more geophagus as one can never have enough geos.
Pearl gourami are nice though, I have 6, you can totally handle 6-10. I'd suggest doing either an even split of male to female, or doing 2 females to every male, I feel it helps bring out the males color. And don't forget about those congo tetras...they might be a little more active but I find its nice having some sort of active group fish amongst cichlids. Seriously, I would suggest looking at my 75 thread, I might be able to give you better opinions and experience related ideas since I'm into the same kinds of fish as you (it seems to me anyways). I started the hobby learning from MFK and being into the bigger fish, oddballs, and cichlids, then worked my way towards plants and have decided to try combining the two schools of aquaria into one super awesome idea.
tl:dr you have a TON of options, and I am getting way too excited FOR you
