I used a Duron 1000 with 512 (or something more) RAM and a Radeon video card, 7100? The card was not supported so I had to use the VESA driver but overall it worked well once I did apt-get build-dep mplayer and then I compiled mplayer from source for my CPU. It worked perfectly but I did have to tweak at it. (I have 10 years of experience with Linux).
Anyway, it is a very nice thing to do, when Eskom still supplied power it ran the whole day in the living room, was nice to cook while watching a series.
I used the normal Ubuntu, though I think XUbuntu will work best for you. I hacked away at things I did not need on the PC so it ran faster without all the extra weight.