I've heard both good and bad about megan. Personally I went with eibachs and couldn't be happier. They lower about an inch and a half on the back and about the same up front. I assume it would be similar on all their kits, but i'll try and find a link.
As far as needing a camber kit or bolts, they are not required for a drop of this size, but you will want to get an alignment after you install them.
If you go for coils in the future a camber kit is almost required or you will have uneven tire wear.
Here is a link to the eibachs, $212 is a pretty good price imo.
http://www.stillen.com/product.asp?id=E ... del=ALTIMA