Current downloads are at mudspike https://www.mudspike.com/chucks-guides-dcs/ AH64 guide will be released on the 23rd of this month. Mudspike is also going down in the next few weeks, so you might want to download those now. Not sure where yet their new home will be.
Not that I'm aware of, but sometime in the next couple weeks it'll go down for a bit to make some big changes. Don't know all the details, but larger files, like Chuck's Guides will no longer be hosted there.