I just purchased a few Yongnuo YN-560 II flashes for use with a light tent (for macro photos) and as this will be my first time using external flashes I'm not quite sure how to power or mount them. So, basically, I have two questions:

1. I will be using these at a fixed location, so I would much prefer to power these via an AC wall outlet. Is that possible? what type of adapter would I need to buy?
2. I am planning on putting one on either side of the light tent and one pointing down from the top. What would be the best way to mount them in these locations?

Thanks!