Get the full rebuild kit from Marlin if you have personal issues with Trail Gear, or get the kit from Trail Gear. I have a Trail Gear kit on one of our FJ40's and it has been fine.
Search Toyota knuckle rebuild on here, Pirate or Google it, there are tons of writeups. The best thing to have is the FSM or a Haynes Manual.
Rebuilding the knuckles is pretty easy, but very messy. Just research it well before you do it so you know what you are getting into, have all of your parts before you start, get lots of shop rags or paper towles, grease, brake kleen, and dive in. Place all of the fasteners in containers per part like the nuts washers and cones in one for the hubs and so forth.
Since you will have it apart, get a set of Marlins HD inner axle seals and a set of Longfields Lifetime kncukle wiper seals that replace the felts. I have both of these and they are great.