The logistics here don't seem to have been planned out at all. To break it down:
Power: Your parents would be pissed to see their electric bill with that gear running. Even if you live on your own, the electric costs would be far more than you could make from trying to sell out the gear.
Heat: You want to put this in a closet? I have a small rack in my office that runs most of our networking, VoIP, and misc network storage at Coke. And even this small bit of gear puts out enough heat that my office has it's own dedicated A/C unit to keep things cool. Closets have zero air flow.
Noise: Pretty obvious. And if your plan on eliminating noise is to 'close the door', then see the above.
Redundancy (Power): You would need fairly massive APC units, since generators are obviously out of the question. These tie right back into my first point. The alternative is _not_ having backup power, in which case any time your house has an outage, all this gear goes offline. I hope you like fscking.
Redundancy (Network): A single business line? Absurd. Residential/"Business" ISPs are finicky at the BEST of times. Not only will you likely never be able to deliver what you promise on network speeds, but you'd be very lucky to actually hit 90%+ uptime any given month.
This isn't even touching situations such as professional hands-on tech work, parts shipping, or the fact that nobody is going to trust "gear running from my house, yo". Instead of trying to make a quick buck from it, _maybe_ rack a single 1U and use it for dev/learning.