Best renderer for architectural interiors?

I want to render a simple domestic interior lit only with “natural” skylight from a large window at one side of the room. I need a res of about 3kx4k pixels. I am using a 3GHz P4. I can let it render for a couple of days if necessary. I am aiming for a very believable natural look. Any suggestions.

indigo , if you havev a new machine one hour will make it