You may have heard of the 1% or 2% rule. People who follow this rule say you should at least get 1-2% of your purchase price per month on a rental property. Some people will only invest if they can get 2% or more, others 1% or more. If you're buying with a mortgage, add closing costs to the purchase price.
Based on the data you've given, your best case scenario is you buy a property for 180k and get 950 in rent:
Both units: $1900
1900 is 1% of 190k.
In this case it seems like you'd be OK. However, do the math with adding closing costs as well. Also, insurance at $1500 a year seems high to me, but that could just be area dependent. I have a 2 unit built in 1896 and insurance is just over $800 a year.
Another "rule" of thumb to consider is the 50% monthly rule. This states that you should plan on having 50% of rent revenue go to the mortgage, taxes, insurance, vacancy and all expenses. If you add them up, and all expenses end up being more than 50% of monthly rent, then you've "broken" this rule.
Based on your info given:
Monthly Expenses:
Mortgage (at 4.5% w/ 20% down): 730
Taxes: 183
Insurance: 125
Water: 60
Maintenance: 333
Total monthly expenses: 1431
Monthly revenue: 1900
Net:$469
Expenses are 75% of revenue!
Here you can see you've broken the 50% rule by quite a bit. And this is kind of a best case scenario as well. ALSO, this doesn't take into account vacancy.
PROS: Seem to get high rents in your area.
CONS: Purchase price is also high.
I don't know what area you're in, but if there was a property like this in my area, I would not go through with it. Mainly because in my area (Grand Rapids, MI) you can find 2-units for ~100k that rent out for $750 p/ unit or more. But you're area is probably different.
Hope this helps! I'm sure if I missed some things others will chime in with answers.