I would go for genuine parts from TPS so you get the latest revision of the part (ECP buy the old superseded stock with the factory markings ground off- its superseded for a reason) and use a good specialist who knows the vehicles inside out like Bognor Motors. Even vehicles in factory warranty can be serviced at somewhere like BM as they use genuine parts and follow ELSA.
If you go for the cheapest even out of warranty, I’m my experience you are rolling the dice, BUT for some people this is the only option and I get that, unfortunately it could also cost more in the long run.