This looks great! Well done, really useful upgrade.
You have mentioned, you think about PU replacement. I would consider different manufacturers, not only the obvious one. I think, the Classic 57 are good, but you can possibly get even nearer to the classic vintage ES 335 sound trying an alternative. Since you always buy PUs "deaf", this is a very hard decision to make. I was looking around for an alternative to the Classic 57 and found out that PUs from LeoSounds or Bare Knuckles do the job very well. After the e-mail contact with the owner of LeoSounds, I decided to go for his pickups, hand-wound, made entirely with US vintage components. He proposed to set a custom pair: for the bridge a warm and creamy PU, for the neck a replica of the original PAF. I followed his suggestion and my guitar sounds great now. The PUs are not that hot (or have less output) than the Gibson ones, but in my case, I play through Marshall 1962 RI, it is an even better thing having more control. I can really start with a very clean and warm jazzy sound (which I do not play) and end up having classic rock sound. This PU combination gives you an endless sound shaping possibilities. The PUs are not very pricey in Europe, I paid 200 Euros for both PU incl. covers.
I cannot say very much about Bare Knuckle PUs, but I have heard, the are very good as well. And at least my luthier did not look very happy hearing, that I was for Classic 57. But the sound is a matter of taste, yo can barely argue. ;-)
It is just an idea to consider and I am sure the Classic 57 will meet your needs. Good luck with your further upgrades.