Just a heads up on the Toyota head gaskets, make sure you get the metal MLS gaskets from them. I think the old graphite composite ones have been superseded to the metal ones, but if not, make sure you get the metal ones. It is not that bad of a job. I rebuilt mine from the ground up with new Toyota bearings, pistons, rings, gaskets and oil pump. Make sure you follow the FSM, it has great step by step info if you have never done it before. I can get a HG job done in about a day, not accounting for the heads to be milled.
That's another thing, make sure you have your aluminum heads resurfaced at a machine shop. I have paid anywhere from $25-40 per head in the past. Usually they are the culprit of a blown head gasket, and replacing the gasket without milling the heads is a waste of time. Also make sure you have, or have access to a good torque wrench. Another good thing to look into is replacing your t-belt and water pump at the same time, as you will have to remove the belt to do this job, and you will have nice access to the water pump also.
This is very good advice. Not sure how many miles you've on your rig BUT since you are set on replacing the parts - you might as well get into it good:
You can't buy an entire "set" from Toyota but other items to consider (that weren't mentioned):
* when the heads are off, get into checking the valve clearance. If specs are close I'd leave it, if they aren't as close as you're comfortable with, get your shims ordered so you will have them in time to get it assembled again.
* definitely replace the "rest" of the Tbelt/water pump components such as: tensioner, idlers, cam seals, crank seal...etc
* I'd also do the intake manifold and plenum gaskets
* fuel injector seals and o-rings,
* valve cover gasket setup (plug wells and end plugs)
* buy yourself a tube of toyota FIPG
* buy yourself a real manual so you can turn pages...etc
* fab up, rent, borrow or buy a crank holder tool
* consider pulling the whole motor and checking out/replacing your clutch and being able to work on everything while it is "out" of the engine bay, it makes things VERY easy
* get new head bolts