PC CPU help

Been looking at a cheap barebones unit that needs a Hdd and a cpu as well as a few other bits.

Aparently it has a motherboard supporting Intel P4 Socket 775 Single core CPUs, and recomends an Intel Pentium 4 775 CPU.

Is that all that will fit? or are there any of the newer ones that are backwards compatible?

What would the STW boffins recomend? Mainly for DVD’s music, photos, internerd etc?

Thanks

which barebones?
very possible there’s core2duo support, maybe core2quad, almost certainly some kind of celeron support (some of those are handy for low power usage).