You thought I was kidding
I have been meaning to do this for a while for myself so you are in luck.
pH meter - top of the list for a reason. Apera or comparable QUALITY ph tester. Get a TDS/PPM/EC meter, but even the cheap ones work well. I used the one that came with a zero-water filter for a year
$50
https://www.amazon.com/gp/product/B077Z6LF91/ref=oh_aui_search_asin_title?ie=UTF8&th=1
Light - HLG-260w V2 $357.99 (what I have) or the HLG-320w V2 $407.99 (what I'll upgrade to when the other one dies.) How much each plant can possibly produce is based on the wattage. More is better, to a point, but if you put too much in a small space you have more heat than can be easily removed.
https://growerslights.com/collections/horticulture-lighting-group/products/horticulture-lighting-group-260-watt-xw-quantum-board-led-kit?variant=8194589425765
https://growerslights.com/collections/horticulture-lighting-group/products/horticulture-lighting-group-320-watt-xw-quantum-board-led-kit-v2?variant=12588746342501
Exhaust - AC Infinity Cloudline. You will lose one foot of height in the closet with this and a cannister but it is worth it. The carbon filter cannister will cost another $50, doesn't really matter which brand. Cheap is good if you can vent it into the attic.
$139
https://www.amazon.com/gp/product/B074XBXFPD/ref=oh_aui_search_asin_title?ie=UTF8&psc=1
RO water filter. Start with 0ppm cheap, then control everything that goes into the water. It's supposed to last a year, but it's rated for 50 gallons per day, so no telling how long it'll last.
$70
https://www.amazon.com/dp/B00LKF09IW/?coliid=I7OC3BE992BJK&colid=2GEB3TZOJW2LZ&psc=0&ref_=lv_ov_lig_dp_it
small oscillating fan
$20
https://www.amazon.com/dp/B0711892YZ/ref=dp_prsubs_2
any little fan will do, but make sure it has a mechanical on-off selector so it comes back on with the timer. Got one that had a push-button on-off, and luckily I noticed that it had to be turned "on" every time the lights came back on. I stuck a different one in quick.
If you want to know any why's or specifics, hit me up on my thread, I'll even post pictures LOL
https://www.rollitup.org/t/superskunk-manifold.982650/