CPO Printing at Kinkos, just have a material question

[Squeeky]

Ok before I get flamed for using Kinkos please read the entire post

I did some color changing on the fusion artwork to match my green t-molding and going with an all black button setup.   I had my marquee printed and I was very happy with the job that only cost me $13.  (Yea Corporate discount!) 

Now when it comes to printing the CPO it measures roughly 34"x15.5", however the center of my trackball is 8.25" from the top and I would like it to be in the center of the image.  Therefore I intend on printing the CPO 36"x18" this would give me some play, and the ability to trim down after lining up.

Kinko's qouted me 5sq ft for the job, and it would cost roughly $69.95+shipping to print same size image are mamemarquee.  I have a plexi cover that I will be using, however I fear that is some moisture gets under it will warp the CPO.  That being said I have the choice of the following materials and prices, just would like some input.

Photo Semi-Gloss Paper = $53.42
Polly Gloss Paper = $36.21
Vinyl = Roughly $38

Let me know your opinion guys,
Squeeky

[waveryder]

Squeeky
If its going under plexi a glossy format of paper is not really neccessary. More important than the paper format is the ink they use. If your going with a vinyl, make sure that they are using UV pigmented inks, that way you still get the glossy effect from your plexi. UV pigmented ink is pretty much watertight, the moisture wont effect it or the vinyl, it wouls effect paper though. Hope that helped. My £0.02

Incedentally I went to the equivalant to kinkos today in the uk and had my marquee and instruction card printed on 300gsm glossy glossy film, for backlit images,  for £1.85 thats about $4. Shouldn't flame people for saving money!