As others have said, the layout and navigation on the site are well done. I briefly played with the Hardware Configuration and have a few suggestions:
1. You should have pictures of the "Lighting FX" options so users understand what they're buying.
2. It might be useful to have a meaningful comparison / breakdown of the different component options. I imagine that your site is catering to PC gamers who don't necessarily have the in-depth technical knowledge to build PCs themselves. If that is the case, listing raw specs alone probably isn't going to be very useful for them. If I'm a user on your site, I might ask "Why would I choose the $240 sound card option over the $100 sound card option?". It's not obvious to me what additional features I get from the more expensive upgrades.