I suggest you get one good power cord for starters, for your Pass Labs integrated. You can build it yourself, yes, nothing wrong with it, but not sure the parts alone will cost less than $50 (good parts that is), let alone labor.
One of the nice gents in these forums (forgot the name) swears by these Chinese power cords:
https://www.ebay.com/itm/202808747120?var=502967448569They are in your budget, and you don’t have to spend a minute of your time.
Or look for a used Shunyata Venom NR v10 or HC.
Kudos for having the willingness to experiment and for overcoming your biases