I'm back with good and bad news.
The good news: is that the company that sells tiles can take a picture (photo, or jpg drawing like the ones we have), rasterize it into tiles, and lay it on sheets for me! Then the workers just have to put the sheets on the wall instead of individual tiles.
Semi-bad news: They won't do the 5cm tiles. They will only do 5cm tiles in large sheets which messes up too much with our palette since some pieces use only a few tiles of certain colours.
The bad news: They won't even do some entire sets of colours. The purples and aquas are completely non-doable. They showed me a new palette that I took a picture of and the tiles are now reduced to 2.5cm.
Good news again: Since they will lay them in sheets for me based off of an image we can actually do four times the resolution in images. So I will either take the current images and just split each 5cm tile into four smaller ones, or possibly take any new awesome higher resolution art if anyone decides to supply some by tomorrow.

I was very upset upon hearing all this. When i had gone the first time i explicitly asked if we could use small numbers of some colours and that all the colours were available to which i was answered yes. They did not think things through to tell me about colour availability or size. This is a typical problem in China so i'm not super surprised.
I actually had asked when i was there the first time if there was an easy software way they went about doing mosaics; must've been lost in translation.
tl:dr
The resolution is now with 2.5cm tiles and there is a new palette. If anyone can change the colours of their art to match it that would be cool. If not i will let the computer software that they use do it for you. Also the possibility of higher resolution art to match the new tile sizes would be cool to consider though we need to order these things quickly.
I will get this done one way or another.
New pallette
http://www.freeimagehosting.net/80334
