Proper instllation of a new window A/C unit on a Aliner

[a11igat0r]

Ok so... Im back.  Did you really think Id be gone long?

So I bought the Aliner.  Doing work on it now to get it all fixed up some.  Its a work in progress.

Next on my ToDo list is to replace the A/C unit with a better/quieter unit.

Now, first, I know the way they installed the one thats in it now is not really how it should be done. 

The way the A/C is situation on my particular camper is.. its on the driver side under one of the bench seats.  So taking it out and replacing isnt really the issue.

Specifically what I need to know is.. what materials do I need to:

a) properly stabilize it securely, mounted level, and minimize rattling?  Will just some sort of foam blocks work?
b) How can i insulate it so that the warm air goes out the side vent and not back into the RV?  I was thinking about just going to Home Depot or something with the dimensions have them bend a sheet of metal (or something) to fit and just secure it over the A/C unit with some sort of padding around it.  Will that work?  I need the most relatively easy way to do this because I wont have alot of tools with me to do it.

Im open to suggestions. 

I will say... ive searched the net for how to's on aliners... and unfortunately you dont see a whole lot out there. 

[John From Detroit]

I think you have a good handle on it,  For framing I used wood on the window units I installed, then (Depending on the size) you may need to use some sheet aluminum or fiberglass (Boat repair) products to finish the job.

I put mine in a front window on the trailer I put iin, no extension out the side and I was able to put it so the "Hot side) air was all drawn from the outside and exhausted outside just like if it was in a house,, I did add some metal bracing to absorb bouncing by the trailer as I hit potholes.

Worked great.