There are a few factors to consider in matching pumps for beckett skimmers. Industrial quality ones like Iwaki pumps are well reputed for quality, reliability, resale value, good resistance against heat-transfer to the water, 24hours running, power vs electricity consumption etc.
IMO, get Iwaki pumps.... really 'no fight' comparatively to other makes which may be cheaper.... remember the chinese saying about every cent is reflected in the value of the goods.