I do have two males. They ignore each other a lot of the time and occasionally seem to cuddle. They always feed side by side, though, and I have *never* witnessed any bad intent from either of them to the other.
You can have several of them in appropriately size tanks, but obviously you need some females to disperse the "aggression." With six of them, I'd use 3 and 3, or if you can stand to have more females, 4 females and 2 males.
Here is a tank that uses several pearls...
Out of your list of choices, I'd choose neons, cories and rasboras. Dwarf gouramis are out, IME. My little dwarf gourami is the only thing the pearls did not jive with. I've got a cherry barb too and he's cool with them and vice versa.
I dont think the glass catfish would look nice with the pearls, but im sure they'd get along. I also think the rams would end up being "equals" in terms of being the centerpiece fish, so I'd avoid those too.
I think scissortail rasboras would make a great contrast, being that they are silvery and thin. Neons/cardinals *always* look nice in schools, esp, against pearl gouramis.
I think Panda cories are the cutest...and (this sounds silly) when they are out near my pearls, they just look like they match