So hopefully after going through your Derby build you'll finally take my advice seriously :D!
With your Derbys you should be able to run in the high 20s up front and low 30s in the back as long as you choose a good tubeless ready tire. Of course, you know why I'm partial to Maxxis but despite that I honestly find that the TR versions air up well, wear pretty well and are quite burp free with any reasonable tire pressure. I've run them down to 22 psi front and 25 psi rear but that's pushing it (no burps but a serious risk of bottoming onto the rim).
I'm also experimenting a bit with Schwalbe Super Gravity tires but find that they're very sensitive to tire pressure and are heavier than I like. At lower pressures the tread squares off quite and makes steering very heavy. At higher pressure they seem to lose their advantage of the stiffer sidewall.
For tape and sealant I've been sticking with Stans because it is simply tried, true, trusted and is widely available.
I've gotten to the point that I don't like the feel of tubes at all. I'm tubeless on my mtbs, CX bike and road bike. I'll run tubes when testing non-tubeless tires but that's it.