The smaller bullies seem to keep well clear of my koura, but the full grown ones seem to get the odd fin niped. With the bullies it would be best to get a male and a female or two females. Best bets would be Upland, Cran's or Redfin bullies.
The next thing to think about is keeping it cool over summer, 1.25 to 2l bottles of frozen water will help lots.