You'll need to render separate parts and print individually with possibly slightly different settings. Main settings to adjust apart from obvious dimensions (fan size, spacings, ...):

• model_type (you'll want one of each. "demo" is just for thingiverse, you can ignore that type)
• model_end_type (you'll want one of each, combined with left and right model_type)
• side_cover_opening_x (set to 0 for the final end piece so it has no hole)

Other parts I used:

• Fans are 80mm Arctic P8 PWM PST, but you can also get regular fans if you want to skip the PWM speed control
• For magnets I used 6x3x1.5mm magnet from amazon. You'll need about 100 of those for 8 80mm fans so that it holds well enough and doesn't fall off too easily from the radiator.
• Get 80mm fan grills if you have pets and are worried about them getting their paws in the fans
• Screws are regular M5 fan screws so get a bunch of those!
• For the electronics, do whatever you want, but I got
  • some cables
  • 12V power supply. if it has a barrel jack to wire adapter, you should be able to press fit it into the hole in the control box cover plate
  • https://www.amazon.de/dp/B0B39DRGTX
  • a PCIe 6pin power connector with some cable for wiring up the control board. salvage from an old PSU or buy a crimp box.

For printing, I turned the middle pieces on the side and printed with supports.