Noctua are excellent coolers, pretty much the best there is for air cooling, although a bit pricey (and bretonian colors, ugh).
I know it's a bit of a gamble but for monitors you can save on south korean AOC/Crossover panels, they are quite nice price-wise, just ain't gonna have bells and whistles (or english manual) normal brand names do.
Not really worth it unless custom building is not an option. I don't think they're bad computers per se, but they have always seemed overpriced for what they offer.
My build is complete and running smoothly! I'll post a picture or two eventually.