I decided to buy a pump head kit by Whale and also a strainer for the inlet and a surge damper for the discharge. I found that Whale have upgraded the pump output and the connections are now 15mm instead of 12mm. This required me to get 15 to 12mm reducers which didn't work very well as they were not gripped properly so I ended up using them with some 15mm elbows I got from Screwfix.
The end result is great, plenty of smooth flow and the strainer will protect the valves from ingesting anything detrimental in the future.