Rather than a 'kit' I tend to buy the bits I need by part number so I get more control over the branding. Paddocks tends to supply a lot of Britpart own-brand stuff by default but LR direct usually offers a choice of brands where available so it's easy to avoid Britpart. While you're at it, it might be worth ordering replacement bolts by part number so you can renew them ll at the same time, plus gaskets etc. as they're only pennies and it's good to know everything is nice and tight with new gaskets and fastenings.
As has been said before, Britpart is a wholesaler, so in fact they supply a lot of OEM and even Land Rover branded stuff too. It's their cheap'n'cheerful own-brand stuff where the tolerances are a bit approximate and the reliability is disappointing.
Even Britpart can't get the lock washer wrong, surely?