Can I...

[UP UP AND GUPPY]

Put 2 Powder Blue Gourami's in a tank with 2 Dwarf Gourami's?

 

[CAPSLOCK]

What size tank?

They're pretty territorial, so the 2 established gouramis will most likely see the new gouramis as an intrusion into their territory. I wouldn't try it in under 20 gallons, and even then I'd rearrange the tank when the new ones are added to mix up the territories.

 

[UP UP AND GUPPY]

Well it is going to be a 20g and the stocking would be this:

2 Silver Lyre Tail Molly (male)
2 Yellow Lyre Tail Moll (male)
2 Dwarf Gourami (male)
2 Powder Blue Gourami (male)

I dont want to risk any of the fishes lives though so before I make up my mind what would you suggest instead of the Powder Blue's?