Imaging software is a godsend for that sort of thing. I ended up using BartPE for something like that, and it worked great – it has a free imaging program on it. You only need a removable drive large enough for all your files since it’ll compress everything.
Perforated galvanized plumbers strapping. While most of my equipment is wall mountable, I used exactly this sort of thing for all the power supplies.
Likely similar to whatever you’re planning to use with the plastic strap, but more metal is more betterer