Ooof. ‘Just out of warranty’ suggests a year or so… early for a water pump. What make was that?
If it were me, I would go for the LR OEM part. It’s probably £100 more than the others, but given the job, I wouldn’t want to have to go back in and do it again early. That said, I hear some good things about Gates. Never used one myself.
Of course, google is a mixed bag of reviews, which ever flavour you pick.