This is where it gets confusing. Also, there have been some mind-bending facts presented, but for what it is worth, I have a conclusion that I am satisfied with.

Veco (Climma) uses Calpeda pumps and brands them with the Climma brand. When they do this, they assign a Climma number. The numbers posted for the Calpeda pump from http://www.penguinfrigo.co.uk/ are actually Climma numbers, not Calpeda. The Calpeda number is BCM20/E for the original AC saltwater pump. That "Climma" pump at Penguin is a Calpeda BCM20/A. Calpeda no longer offers a BCM20/E. I am not sure what the difference is between "A" and "E," but I suspect it is electrical because both of these pumps have the same GPH range around 1200. I know that years ago Calpeda had 2 versions of the BCM20. The one Amel installed had an aluminum capacitor, the other a plastic capacitor. There may have been other differences. I also know that if you were unfortunate to buy one with the plastic capacitor, it would melt with heavy use in the tropics.

I am now convinced that the best pump for the A/C is the Calpeda pump. Someday, March may make an encapsulated magnetic drive pump in the 1,200GPH range. When they do, my preference will change. That said, the March TE 5.5C-MD-AC will do a great job, however, you must keep saltwater away from everything except the inside of the pump housing, and you must treat the painted sheet metal case with CorrosionX. You must also immediately clean any accidentally spilled saltwater from the casing and then treat with CorrosionX. 

Unlike Eric's experience with rust appearing on a similar stored March pump, I did not have that happen for the 4 years I had one stored as a spare in the engine room, but I had coated it with CorrosionX only once when I stored it. 

I hope this helps.