If I go this route, what (if any) modifications would need to be made so that the power supply was only putting out the 48V? I assume that some sort of change would be needed to make it safe, but I'm no engineer...
I've read through the assembly and wiring instructions, but don't know enough to guess what may or may not be necessary.
There'll be a schematic included in the kit.
The PSU is divided into (3) parts or sections. The first section is the +48V section, the second is the +18 section, and the third is the -18 section.
What you can do is just leave the 2nd and 3rd sections unpopulated. i.e. don't solder any of the components on these 2 sections if you only want 48V working.