They're all the same ,well sort of,yours is a six meter head pump,pumps with a number five (i.e CP 53)on them are five meter head pumps.
Grundfos are the best,equivalent for you is the 15-60,however they are expensive. I usually go for the cheapo Myson ones (same as the compact I believe)at about half the price and guarantee them for a year.
BG fit the Myson ones which are branded as BG pumps.