Don't stop at 600V - that would be a 1N4005, and a 1N4007 (same price) can handle 1000V. I buy them by the thousands (okay, just once, so far) and opt for the lowest DigiKey price - in my case, it was a mini-reel from Diodes Incorporated - I think they were two cents each or so.
Here's some cheapos that will work just fine for any 0-1000V rectification job, 1A max:
https://www.digikey.com/product-deta...7-1-ND/3511542
For the Zeners, I've found that the kits from Banggood/DhGate/AliExpress all are decent enough - you can usually get like 150 Zeners in the popular voltages for 3.99 shipped - to the US. I dunno if China has an agreement with Canada Post about the E-packet stuff.
https://www.banggood.com/300pcs-2V-3...l?rmmds=search
As to resistors, quit looking for old-value resistors - you gotta think "E24" values, so 47 or 51 ohm resistors - and there I pull from old chassis. Generally, I can go up in wattage a bit if size permits on my own stuff, but for others/customers, I go with the correct wattage. If I have to buy, I again look for the lowest price. Square sand/cement "PW" (a TRW/IRC designation) resistors are what I use most - they are getting harder to find, so some overlap into the NTE stuff - and I get them locally.
http://www.ohmslawcalculator.com/e24-resistor-sizes