Basically there are 2 options then, Freevo and Mythtv. I´ve used both (now using Mythtv). I´ve written howtos (see the tips and tricks forum) how to install these. As with everything else: if you know what you are doing it is easy. Mandriva 2006.0 works perfectly with mythtv. I don´t know about freevo with 2006.0 but I doubt you will have problems. I think you should just install it and see how it goes. if you need specific advize for som eof the problems you will run into post them here.
Good luck.