What thickness aluminum for interior wall coverage is good? and where 2 buy it?

[LAWFISH]

OK, I am planning on buying a few sheets of aluminum and using it to cover some interior wood walls that have wayy too many holes drilled in them and that we just simply want to change the look of.

I watched the DIY videos and liked the idea of using aluminum to cover the bathroom shower wall for a water tights wall, but am also going to do several more interior walls the same way. However, what the video does not tell you is what thickness to use. How thick does it need to be to avoid being damaged too easy, and where is the best place to buy aluminum locally?????

And for those using aluminum, what electric sheers do you use, what is a good brand. I have some air sheers but I dont think they would cut nice enough for this application?

Dave