I just put a Panasonic head unit, 2 amps, 2 sets of new speakers (door and rear panels) and a subwoofer in my truck, doing all the installation and wiring work myself.
I used the factory bracket, and with a little situating, was able to fit the head unit in a sturdy position ("locked" back against the two turned-in tips of the bracket and the other two tips underneath it, using the same bottom tips for mounting the standard Toyota pocket, which you can buy anywhere.)
Make sure you buy a wiring harness and follow the wiring directions on the head unit. Before you connect anything, use a voltimeter or multimeter to ensure you're getting power to the proper wires. A lot of trucks have loose/unconnected wiring or wiring that was redone incorrectly (see: moron PO's and dealer installed alarm units that broke 5 minutes after they were installed).