I pay about 9 cent KW/hr, not sure about capacity... I have room left in my circuit breaker if thats what you mean. How do I find out about capacity?
I'm not looking for a big miner, as I understand they are usually very loud. My wife, doesn't want to deal with something that sounds like a shop vac constantly going off in the garage, especially as we have an 18 month old that takes naps during the day still.
9 cents/kWh is a bit on the high side for any large asic miner and given your wife, it makes things even worse, but as far as the little baby is concerned I believe they will sleep better with the noise of the asic miner, babies love white noise.

Do you have an idea how many I can expect to mine on a monthly basis with one?
if you get Apollo with 3th you would expect to make about $12 or 0.00038
BTC per month (before the power bill).
You can use this simple
calculator to calculate different hashrate, but keep in mind that these numbers do change depending on the difficulty and price of bitcoin.