Recommend a wall unit
 

I'm needing a wall unit to cool and if not too much more money heat also.

12x10 = 120 sq feet
Wall mount.
5000 btu ?
Not to be run constant.

I have a ceiling fan, a standard size door, and a nice big window facing north.
If the unit was put in the window we could see it from the house. This is in my nice shed with drywall, cement foundation, and shingled roof.
What brands seem to give the least amount of frustration. I only want to cut one hole in the wall. The LG LW5012J is only $99 here, but It's a window unit.
How hard is it to make that work as a wall mount?

Thank you in advance.