Gourami's are terrible tank mates for bettas and should not be recommended, If you're looking for tank mates for your boy you could try something like a small group of WCMM's or Africn Dwarf Frogs or Shrimp
They are not nearly close enough relatives to try mating Kieth. They are both anabantoids but guppies and swordtails and even Limias are all Poeciliids, no way they will mate either.