I'm sat here wondering how the beans would have got in the can!
Seriously Michael, all joking aside - if you ask for opinions, you are going to get them. As I said in an earlier post, I admire your ambition, but there is a difference between ambition and a realistic, workable business plan.
For what its worth, I have spent 27 years helping build a business, one slow step at a time. Maybe we lack ambition, but we don't owe the bank anything, and I sleep soundly every night. Over that time I have watched some businesses with ambitious ideas grow and succeed, but have seen a lot more go bust when the business plan wasn't as great as the ambition.
To leave you on a positive note - have you thought about getting together with a few other engineers and forming a co-op? That would get you over both the holiday/illness issue, and give the customers some peace of mind that they wouldn't be left in the lurch.