First off, if you wanna single someone out (me, wow!!!) just PM them. Otherwise just ask the question you need answered, and someone will answer you (whether it be me or someone else.)
Second, just use the Male and Female with the Female holding the Everstone. It should give you 50% of your eggs (estimate) with Modest Nature. If you wanted some of Feebas's Egg Moves use a Male with the move you want it to know, and the eggs will learn it, same for HM/TM moves.
They may not get along, but they will still produce eggs, but if you want them more friendly with each other, then Tame them (keeping them in party, hold Sothe Bell or other item, give Calciums, Potions, ect.) and the more they are tame, the better they get along. The better they get along the faster they produce eggs.
Note: the Everstone trick only works in Pokemon Emerald. Also use a Camarupt, Magby, Magmar, Slugma, or Magcargo to speed up hatching (also exclusive to Emerald)