Change the 9590 to an intel 6900k, change the motherboard with it to lga1151 socket
Bump upto a DDR4 ram slot in possible.
Gigabyte > MSI
1500 PSU too much, try 1200
go with water cooling if this is a dream build.
You dont need external sound cards, the motherboard onboard chipsets are much better and are included.
Go with BenQ 144Hz monitors if you can change.