Why not Xubuntu then coz its meant for the older pcs.But you'll have to install OOo separately as it comes bundled with Abiword and Gnumeric.
If not impressed by Xubuntu,then you can also try Vector Linux which is supposed to run over PCs with minimal configuration.An excerpt from the webpage
"This is our foundation edition - a freely downloadable distribution, which includes best of breed applications for every task and is specifically designed for use on older computers with slower processors and less RAM, or for those who appreciate bloat-free distributions. Features include the fast Xfce desktop environment, multimedia, email, web browsing, word processing, spreadsheets, and networking applications. It forms the stable base of our other editions and is ideally suited for an Internet workstation."
Follow the link here and choose the version that seems to be best for you
http://vectorlinux.com/products
Also follow up the Hardware req. it quotes,that might impress you.
The only hiccup includes that its not a live CD (but it has its own advantage for this,the minimum RAM and Processor req. gets lowered too)