What do you guys think?

Lately I've really been wanting to get either a needle nose fish or a peacock eel. Well my two largest tanks are:

20G
2 pictus cats
2 mystery snails

and

55G
5 Red tailed Dalmatian Platies
5 Albino Cory cats
3 Sunburst Platies
1 Blue Dwarf Male Gourami
2 Canas Apple Snails
5 Long Fin Red Minor Tetras
11 neons which I'm giving to a friend with a 55G that she just got and will be adding bio spira
3 dwarf sunset platies also going to the same friend.

Anyways, I have a feeling that the needle nose isn't going to work (haven't researched them much but am going to after I post this.
The peacock eel is suppose to be fine (according to the internet) with the platies, corys, snails, and all other fish. I don't think I could/should put ether of these in a 20G since they get between 10-12"
Well the point of all of this is to get some opinions on A) if this would be over stocking my tank once the neons and dwarf platies are gone and B) if this would be appropriate housing?

Yes, I knew this but I know a FEW semi-aggressive do ok with community however I just read that needle fish can get 16"!! So thats out for sure. I don't have the room nor set up for him so now I'm looking strictly at the peacock eel.

OK, I did some more reading on peacock eels. According to several sites, a peacock eel would be fine with my fish and I'm not seeing anywhere that they need to be kept in groups. I'm getting different sizes but they are all saying ether 10" or 12" at most. I've read that they must have a cave to hide in which I have no problem buying one. I've found out that they generally stay hidden in the day and are out at night and feeding time. I know they have to have live or frozen foods. I already keep frozen foods on hand at all times and I think I may order some red wigglers for the peacock eel if I get one and for my other fish that would probably enjoy some
So, all I need to know is do I have enough space to add one? Maybe 2 or is that just pushing it?

Anyone have any thoughts?