55 Gallon Stocking?

[Kelsyann]

Okay so my uncle gave me his 55gallon with some fish already in it. Right now There's a filter rated for 75 gallons and 3 heaters spread around to keep the heat at 78 degrees F.
Current Stocking:
1 Male Opaline Gourami
3 Harlequin Raspboas
3 Black Skirt Tetras
1 Silver Dollar
2 big Plecos
15 or so cories, but we're giving some away to leave us with about 5.

So my question is this: I know the raspboas, tetras, and silver dollar need more fish added to their shoals. So I'm thinking of getting 3 more of each Raspboa, Tetra, and Silver Dollar. Now after I do this and reduce cory numbers a little, do I have room for any more fish? My parents are bugging me saying they want "prettier" fish in there and to not add more of the same kind. I tried to explain to my dad that they are happier in groups, but he has the "they're just fish!" attitude. So I'm trying to make everyone happier here.
Thanks for any help!

 

[MermaidMel]

Okay so my uncle gave me his 55gallon with some fish already in it. Right now There's a filter rated for 75 gallons and 3 heaters spread around to keep the heat at 78 degrees F.
Current Stocking:
1 Male Opaline Gourami - 2 females perhaps?
3 Harlequin Raspboas - it's Rasbora hun - you could do with having 8-10 of these
3 Black Skirt Tetras - 3 more
1 Silver Dollar - I don't know much about them, how big is this 1?
2 big Plecos - probably worth getting rid of these, they are messy and add a lot to the bioload
15 or so cories, but we're giving some away to leave us with about 5.

So my question is this: I know the raspboas, tetras, and silver dollar need more fish added to their shoals. So I'm thinking of getting 3 more of each Raspboa, Tetra, and Silver Dollar. Now after I do this and reduce cory numbers a little, do I have room for any more fish? My parents are bugging me saying they want "prettier" fish in there and to not add more of the same kind. I tried to explain to my dad that they are happier in groups, but he has the "they're just fish!" attitude. So I'm trying to make everyone happier here.
Thanks for any help!

 

[Kelsyann]

So today I got 3 more Silver Dollars and 3 BST. Petsmart didn't have the Rasboas, I'll have to look elsewhere for them. The tank is starting to look properly stocked now, but my parents still want a centerpiece fish. Any suggestions?