Get THIS:

If you want cheap wheels:

Plastic Pulleys
Zip Ties
Epoxy

If you want nice wheels:

Standard wheels from home depot: Choose ones that will fit the aluminum channel.

Two Aluminum Channels: These are used for the wheels to slide back forth on. They slightly dip when the laptop is docked. But they are not moving anywhere.

Two steel cross rods: These are used for the horizontal section. They are the black bars attatched to the wooden block

One wooden plank of wood: Arm Mount hangs from this.

TV mount: The TV mount I bought was purchased for 20 dollars on EBAY, this is very adjustable and easy to mount.

Wire Hider: Makes things look nice.

IR sensor: This is usb based hardware, allows you to control your PC with a remote...not necessary but if you want to watch DVD's from a far, its a good investment.

Plastic Tray: The harder the better. Wood would probaly be a better choice here.