Few bits of advice.
Don't put all your eggs in 1 basket. - do something completely different so if the electronics industry colapses he has something left.
Do something he enjoys.
If running 2 businesses, do something that is part time. Ideally something that can be left for periods of time when the other business is flat out.
Obviously, carry out the propper research to make sure the business is viable. Look into hidden on-costs etc.
TBH, the donut van sounds like a good idea to me.
In my case, I run an electronics business, I'm also a partner in a company which builds & operates coin op childrens rides. We invest the time & money to build the site, then sit back & take the income in exchange for 1 or 2 days a week doing service visits.
http://www.airkarts.com/services1.htmA word of caution on your upcoming contract - dealing with big companies is not always a bed of roses. It's quite common for them to screw you into the ground on price, pay months late or even look for reasons to avoid paying altogether. Just be careful and make sure you don't go in with both feet only to find it's quicksand.