Been a tech going on 6 years, and personally, I use a mix of matco/mac/snapon for tools I use commonly (wrenches, ratchets, sockets, etc) and ching chong meow for speciallty stuff like ford can synch tools, etc.
Honestly, snapon's stuff is superior, but for me the point of diminishing returns is low in this situation since a 5 min. visit on the snapon truck will yield you a bill thats 2X your paycheck.
Also, why the fuck do you want to get into this line of work? Are you a masochist? Id leave in a heartbeat if I could afford it, but until the wifey gets her nursing degree im SOL.