With a bare kernel you won't be quite able to
enjoy a Linux-experience ... in fact, I doubt
you'd be able to install it.
or do i have to buy a a version of linux like mandrake etc?
No, there's many freely downloadable distro's.
You shouldn't go and buy it before you know
whether you like it. (Fell free, however, to support
development if you like what you get ;}). ...