Not to discourage you, but,
You're talking apple and oranges between home brewing and comercial brewing. To start, Just the local, state and federal regulations will eat up your love donations and a whole lot more, not to mention all the aspirin you'll need.
Then you will have expenses every month, if you feel like brewing or not or if you sell your beer or not.
A 3.5bbl systems is not viable as a stand alone business.
A rough rule of thumb, for every person employed, you should have 10bbls going out the door(sold) every week to make ends meet. That means, on your 3.5bbl system and you working on your own, you would have to brew 3 times a week, along with all the tanks to hold this, then cleaning, racking, packaging, deliveries, billing, accounting,......etc.
I believe a lot of people have jumped from home brewing to commercial brewing and alot of them are not around now.
Yes, some are still around and very good breweries, but I'm sure alot of them either have second thoughts or would do it differently.
Not to discourage you.
If still considering this, I would recommend you learn all you can about both the brewing and the business side of the venture.
If you can look at a good business plan(ideally for a brewery), this will answer alot of questions for you.
Along with this, if you can, work in a small brewery for awhile, this will teach you alot about what you don't see in home brewing.