So for me (also do IT/Security consulting and repair) I have:
- Clonezilla (multiple versions for different CPU architecture as well as x86 and x64 boards
- DBAN (only for HDDs)
- Hirens Boot CD (for Window OS repair/password resets)
- GParted (same setup as Clonezilla)
- Kali Linux (for security auditing and malware analyzation)
- Puppy Linux (for general stuff/data rescue on old computers/anything I need to boot into RAM for)
- TAILS (it is intended for heavy privacy and security but I actually don’t really use it, but it’s small so I leave it on there)
- SystemRescue (Linux distro for all sorts of rescue purposes)
- Sometimes a Windows install/recovery ISO (per need basis, typically Hirens solves recovery stuff so I rarely go this route for recovery)
EDIT: Also have two versions (x86 and x64) of AntiX for general purpose stuff. Boots into RAM like puppy but I find it a little more useful.
I have these running on a 128 (I think, might be bigger) flash drive that I actually have looped on my keychain. I have found that 90% of the things I need to do can be done from that, and having it on my keys means I always have it ready. Unless I lose my keys for a while that is…
Not a problem, I enjoy passing down knowledge even though I am still relatively new in the field as well (5 ish years). Good luck with the business! Don’t get discouraged if it starts slow, don’t be afraid to admit that you don’t know how to do something yet, and never stop learning.