I'm looking to build a new computer (for c. $1000-$1200) and as my lifestyle may be becoming slightly more mobile, I'm wondering about the feasibility and availability of building a smaller more portable desktop (like a LAN box, as we used to call them back in 2006) for A) Mid to high level Gaming and B) Music Recording/Editing. Basically I was thinking of a reasonably powerful computer that's light and fits in a smallish case (with a handle, or strap, or something).
I built a computer about seven years ago with assistance from friends, but I haven't really been keeping up on hardware and the like since. A bit of research has shown me that it CAN be done, but maybe not by total amateurs such as myself. Is this a possibility? If so, can anyone direct me to appropriate cases/motherboards to start out with? For all intents and purposes, treat me as an amateur who has no idea what he's doing. Thanks in advance for your no-doubt brilliant input!