The MCX gear pump is the best IMO, the electric ones never seem to last, the old electric one Bender used to use was the best electric but it was big, weighed a ton and was expensive.
My PL kit came with a pump marked posi-flo. It worked well for the 6 yrs I ran that sled. Likely still going. They push better than pull so mount accordingly.
The apex motor does not offer the same location as the nytro. It only has the small black threaded cap on the left side of the motor. I assume this would also be a suitable location for vacuum?