All the hosts that I know of work with a Mac. It's the software that you use that may be the issue.
I use
www.1and1.com for all my hosting, and it works fine with my Mac (and PC). I use Adobe GoLive for my software to build the site, which works both on the Mac and PC. I know Dreamweaver also works well on both platforms.
Not sure if 1and1 has their own site builder software, though. I tend to not use those types of software because they don't have a lot of the features I like, but it's worth checking out...