seeking referrals for A/C unit repair

See this message from a Quincy Place NW:

I have an A/C unit in which the fan has apparently died. If anyone in the neighborhood has an A/C repairman to recommend, I would really appreciate it!

seeking CAC system recommendations

See this message from a resident of T Street NW:

I live in the neighborhood and have a home build in the 1920`s that has no central airconditioner system. I am looking for recommendations on what types of systems are best and less obstructive to install in this older homes, based on other residents who have had to install a central air system.

What companies or individuals would you all recommend and give me also an idea of length of time to install one, costs, unit on the roof vs. backyard? The attic has not been insulated and has no venting system so the heat in the home is oppressing at times.

Any advice would be appreciated.

A/C for a basement

See this request from a 2nd Street NW resident:

I would like to install some easy A/C in the basement unit of my house. The windows are too small for a window unit, so I think my options are either (a) a mobile (rolling) A/C unit, or (b) one of those rather flat, wall-mounted A/C units. My problem is that there isn't a window to run an exhaust or water disposal hose. So what do I do? Does anyone have any suggestions? Thanks!