TrueNAS scale, LIS HBA cards, server motherboards with plenty of PCI Lanes ie AMD EPYC, large capacity HDD, just make sure they are CMR and not SMR drives. And Raidz2 is your friend. You will not need 40 drives, frankly you will fit 10,000 films, mostly 4K and 1000 complete TV series on a single 12 drive wide Raidz2 vDev using 20TB drives. That's enough to last 50 years in terms of viewing time.