Hunting cooler on my trailer...

[bigblock468]

So, first of all I am trying to determine exactly how much cooling I need in order to cool 500lbs of meat in about 24hours. (Starting temp approximately 98F). Everything I have calculated says that approximately 3700-4400 BTU will perform acceptably to bring a 4'X6"X7" space with the moose in it down to about 38F within this time. (Assuming an R Value of 25 for the walls ceiling and floor).
First of all, can anyone confirm this so far?

[bigblock468]

Second, tonight I looked at a unit that is using 134A refrigerant, it is 6000 BTU based on 45 degrees and I think this will do me well in my situation. (Please correct me if I am wrong). My question is how much efficiency do I loose by making it drop the temp to 37 or 38?

[bigblock468]

Does anyone have any suggestions how I could build walls that would be comparable to pre-made 4" Foam cooler walls at a reasonable price?

Do you think that the above unit will perform the way I would like it to? I know its a high temp unit and not a med-temp unit which is what I have been told would be best for this type of situation, however it has its benifits for trying to cool very warm meat.

Thanks for any information you can offer....

[bigblock468]

Sorry for the multiple posts, but it wouldn't let me put all of this in one for some reason... I don't think it liked some of the characters I had in one of the paragraphs... so I had to piece it together this way...