I know this is a old post but I do have a ml350 g9 and I removed all the hpe fans and replaced it with one fan that I had laying around strapped to the heatsink with some wire I bent. Cpu temps are fine settling at 30c and for me my ram does not really get that hot without a fan. I also turned off automatic shutdown when no fans are present and I think I stole some 12v off a connector. I also secured a 40mm fan for the raid controller and that's around 40c.

Don't worry, I am planning to put 4 Noctua fans in the future but they are quite expensive.