Personally, I've seen people talk about the issues with the K6 series processors, so I would recommend the Celeron Chips. Since it's in the house and heat is not a issue, the AMD duron's might be a option since they are pretty darn cheap right now.
I do not recommend intergrated video motherboards unless you are going to use a DVD decoder card, other wise the ATI line of cards seem to do DVD quite nicely.
Soundblaster Live card are a nice choice for indoors, since you might actaully get the benefits of 4 speaker output. However, in the interest of cost, you might be better off with a nice SB16. Power's not issue in the house, so any old power supply will do.
DVD drives, the pioneer line seems to be the most popular. I have a SCSI model of their's, and it's nice. I hear good things about the IDE drives.
That's really about it. Throw a Hard Drive at it, maybe ethernet, and you're good to go.