I've given up trying to understand all the various makes and models and what goes with what

I can't even find clear information on the web.
So - £500, what can I get with it? I don't need CD, soundcard or NIC, don't want a motherboard with everything built-in, and after that MSI thread I don't want MSI neither. Oh and I have a monitor, keyboard and mouse. If I could buy a ready-made system to my spec, I would, but I can't.
[edit] I favour AMD over Intel.