Updating my servers firmware (IBM X3550 m3 7944)

[FinOxy]

Hi
I have been trying to update my servers firmware, but I cannot get any OS to install on my server
I have already succesfylly installed truenas scale on there, so it should not be a problem
IBM provides a couple of options, including windows server, and some linux enterprise servers
For me, the point would be not to pay for the OS just use it to update the firmware, for two servers, once.
Here is the IBMs page, but I am going write the options here
-windows server
-SUSE linux enterprise server 10 and 11
-Red hat enterprise 7,6,5 and 4
And VMware ESX 4

The only one availlable for trial would the Suse enterprise server 11 SP4. And for trial, I mean that I don't have to subscribe to anything. 

Here are some specs
IBM X3550 m3 7944
2x XEON E5506
32gb of RAM
SAS/SATA drives