Hi Julian, welcome to the forum!

my 2 cents worth on the pickups.

I’d probably be tempted to get the kit in, build it with the stock gear and see how it plays to your ears. If it isn’t doing it for you then you can upgrade or modify.
Just restating, there is not much wrong with the kit pickups, but they are built to a price and nothing more. If you are chasing mystical Hendrix tone or Dimebag growl, then you might want to look at something up spec.
I have 3 builds running kit pickups and they sound fine, but I’ve also 2 others running SD (Black Winters) and EMG (ZW Set) and they are starkly different (the Black Winters cost more than the guitar they are in, but they SCREAM) comes down to what you are looking for in sound and how much you want to pay for that. it’s all a bit “Ear of the beholder” really.