I have only modded SkyHawks and Lian Li cases. I remove the top panel. This gives clear access to eveything. Some cases come with a removable top LL doesn't. Cut two pieces of 90degree aluminum stock, drill and mount with a cross strap. Drill several well placed holes(small) in the cross strap to bolt using wire clamps or zip-ties to hold up all the unused wiring out of the way of the PSU intake.
There are numerous articles on line about sleeving. Look them up.
Cutting and splicing wires can be tough. Many PSUs have fine stranded steel wire. At ACE Hardware buy some 3/32" copper tubing, use a wire stripper to cut 3/8" lengths to use as crimp unions, touch the bare wire ends in a tin of flux, crimp,solder,use heat shrink and its done.
After the wires are cut,they must remain in proper orientation, the sleeving and heat shrink must be slid on before soldering. It takes me two evenings at the bench to do a VG job of it.
I drill some small holes and use wire clamp instead of zip-ties as much as possible.
It is a bit of work but does look good.
To mod one must have some basic tools and skills. Nothing extream.
Check out the knowledge base at directron.com. There is a small forum there with many ideas and pics.
Galvanized