On mine, I used a pump out of an ice machine. Worked great UNTIL.... until it got a large piece of swarf caught between the impeller and the case (all plastic of course). I was able to piece it back together for a while, but got to thinking. I have a cnc here, why not Make one! So a little time on cad and using the original as ideas, I came up with a casing made out of pvc pipe coupling, some derlin that I had laying around and aluminum for the impeller. Been working fine for a couple of years now! It is based on a "pedestal " design and keeps the motor above liquid level. Cost nil, fun priceless.
Art
AKA Country Bubba (Older Than Dirt)