I'm using PiMame, powering the Raspberry off of a powered USB hub, and using the Ultimarc Mini-Pac as the keyboard encoder. For video, I've got an HDMI-VGA converter from Adafruit, which also converts the digital Audio from the HDMI.
Not a full size cabinet (yet), but I can hook it up almost anywhere and play. I'm thinking of just keeping this, and mounting the Pi and stuff all internal to the console.
The panel isn't heavy so much as awkward. It's mostly empty space. The monitor is a huge heavy beast, but it's what I had around. I don't move it if I don't have to! Eventually I might replace it with a lcd. The trackball I got used on Kijijii for 10 bucks.