I think you're giving up too easily on the Pearl G's.......there are spectacular looking fish that swim with grace. The male would be easy to tell apart from the females & to be honest I had another female before this one & I can still tell the difference from the pictures of both. Sadie, my current female has a taller body shape than Orca had.
Pearl G's also go well with Honey or Dwarf Gouramis, so in a tank that size you could have 2 or 3 of each species, depending on how many Corys you had.
On the Cory subject, I never heard that Bronze or Albino Corys (same species) require a 4 foot tank for more than 6 of them. In fact a 40 gallon breeder tank has the depth from the wall which increases it's footprint allowing for a minimum of 8 if not 10. Again, I wouldn't put 10 Bronze Corys in with 3 Pearls & 3 Honeys but a pair of Pearls, a pair of Honeys or Dwarf G's along with 8 Bronze would be a nice stocking in my most humble opinion.
Waiting for someone to say that tank would be grossly overstocked using the ridiculously lame 1 inch per gallon rule...........
Even then:
8 Bronze or Albino = 24 inches (based on 3" per fish)
2 Pearl G's = 8 inches (based on 4" per fish)
2 Honeys = 6 inches (Based on 3" per fish)
for a total of 38 inches in a 40 gallon tank
OR
6 Bronze or Albino = 18 inches
3 Pearl G's = 12 inches
3 Honeys = 9 inches
for a total of 38 inches in a 40 gallon tank
Hardly an overstocked tank if you have good filtration & some live plants