I use brass, mainly for prototype ballast, I find it easier to keep accurate track of how much weight I have used on a lure. I gave up using it for lips in favour of plastics, easier to work and finish. It's good for prototyping as you can easily try out diferent angles.
I get mine from large hardware stores. You pay too much but the amount that you need is fairly small.
I use 0.6mm with tin snips. It makes a mess of the edges, but it is not difficult to clean up with the dremmel. A bar of polishing compound with the buffing wheel attachment will shift all the scratches fairly quickly. If you don't have the compound, brasso works, but I wouldn't do it in the kitchen, it would be grounds for divorce. Polishing inside a plastic bag works, although mildly inconvenient.
As for using machine tools for the cutting of such small pieces, highly dangerous. Best count your fingers before you start and have a sterilised container full of ice close by. I can't advise you more than that.
