If you want the catfish to spawn, you should put some den-like structures in for that purpose. Old tires are sometimes used. They don't require much. If you don't want them to spawn, you should try to avoid structures that would encourage them. I haven't seen whether the hybrid blue cats are sterile.

When thinking of habitat, I would keep in mind the bottom of the pond, which presumably is already completed. I would want deep areas and shallower areas (structure) well out in the pond: bars, mounds, and trenches. In other words, not a smooth bottom like a bowl, but also not sudden dropoffs that would pose a hazard to people wading near shore.

When I stocked my pond, I put LMB, BG, and CC plus RES all in at the same time, early in the spring. That worked well for me. My pond was no more than � ac, and I went with 25 fingerlings of each species.