A triplex sold down the street for $285,000 and a duplex a block away is pending sale at $229,000, and researching what the rents are, both came in around 1% of the sale price.

Usually you get an open-topped dumpster and put it in the driveway or maybe along the street. 

I would start there or check loopnet and see which brokers are really active, especially in the 20 unit range you're in and call them for a referral.

It's a big house on 20 acres, right down the street from a ministry school that  is doing a $96 million dollar expansion on their school, and has no dorm space.

Is it for a down payment or to facilitate other investing activities?

I am actively looking and in contact with a couple different sellers.

The letter should introduce yourself as an investor, saying that you are currently actively buying in the area and that you thought their building can be a good fit to your portfolio provided it meets your criteria. 

Being born and raised here in Detroit and someone who actively invests in Detroit, I am happy to help you.

., I am wondering if florida is a place you are active investing in?

I think it depends who you ask and what streets you're on.