I recently built a new computer from components (with some guidance from my friend Jim who has more experience in building systems). Unfortunately my Wiki wasn't up and running at the time and I didn't take any pictures whilst building it so there's no documentation of the build itself or the early installation of Gentoo on it, but this page documents its evolving configuration.
http://farm4.static.flickr.com/3444/3971011395_acd8305982.jpg
The hardware was bought from various places including Amazon, Ebuyer and Scan.
Full Home Build Hardware Listing as reported by ''lshw''.
I opted to go with a full 64-bit install on this system.
I've upgraded the motherboard, Hard-drives, RAM and various bits over the years.
Got a new M.2 250Gb SSD and wanted to migrate the OS. This is fairly straight-forward.
Various versions of the kernel configuration are available below
gentoo linux howto article hardware tips portage