I too have a Enthoo Primo I built and used for some time, but because it was too big to fit where I keep my computer(s) it is boxed up in closet now.
I used it with both air and water cooling and loved it in all ways except size.
Your motherboard has about 75mm center CPU to near side of nearest PCIe socket and 55mm to near side of RAM socket.
I think all x16 PCIe are same so you could use a lower one for GPU and use any of a number of big CPU coolers like PU cooler like TRUE Spirit 140 Power, NH-U14S or Le Grand Macho RT. All three of these are extremely good if not the best cooling and very quiet too .. and all will clear RAM no problem. Only the Le Grand Macho RT will not overlap top PCIe socket. The TRUE Spirit is available here in UK on river site but I cannot find any Le Grand Macho.
There are many other top tier coolers like NH-D15, NH-D15S, and R1 Universal to choose from, but few if any are as cool and quiet.
D15 and D15S are, but D15 front fan would be setting quite high to clear RAM and are more expensive than NH-U14S or TRUE Spirit 140 Power.
R1 Universal fans are not quite as quiet and it also costs more.
PH-TC14PE would be cool and quiet but will not fit with front fan. You could mount the fans in pull / pull on back of each tower instead of on front of them.

I used it with both air and water cooling and loved it in all ways except size.
Your motherboard has about 75mm center CPU to near side of nearest PCIe socket and 55mm to near side of RAM socket.
I think all x16 PCIe are same so you could use a lower one for GPU and use any of a number of big CPU coolers like PU cooler like TRUE Spirit 140 Power, NH-U14S or Le Grand Macho RT. All three of these are extremely good if not the best cooling and very quiet too .. and all will clear RAM no problem. Only the Le Grand Macho RT will not overlap top PCIe socket. The TRUE Spirit is available here in UK on river site but I cannot find any Le Grand Macho.
There are many other top tier coolers like NH-D15, NH-D15S, and R1 Universal to choose from, but few if any are as cool and quiet.
D15 and D15S are, but D15 front fan would be setting quite high to clear RAM and are more expensive than NH-U14S or TRUE Spirit 140 Power.
R1 Universal fans are not quite as quiet and it also costs more.
PH-TC14PE would be cool and quiet but will not fit with front fan. You could mount the fans in pull / pull on back of each tower instead of on front of them.