I concur with Blue Bomber mostly and I'll keep it short and simple. I hope that anyone will add or correct me if they disagree.
I won't comment on spring/strut combos.
For chasis support Blue is right (if you have the money). If you get a front bar, in my opinion, you will need a rear upper (3 Pt. or nothing) and also the front under (Cusco), to tie it all in. The front alone will make handling worse. The rear of our hatchback style cars is where we need reinforcement. That's just to start and there are more options, but that should be it for most.
The biggest improvement you can make is with anti-roll/sway bars. Hotchkis is the way to go being that they are "stiffer" and you can get them at a good price street or comp, whichever you prefer. I say street for those asking now. I wouldn't even bother with TRD
. I know there are others equal or untried, but Hotchkis all around is a sure bet for a great price.
LSD. I know it's not part of the suspension, but it should be included. Our cars should've come with it. A big cost saver for Toyota, but it's needed especially if you start modifying the suspension and adding power mods. I can spin my inside wheel more now than stock with a stiffer and lower suspension. The install and cost of one is an arm and a leg. Save that for the clutch replacement.
Most here will comment you don't need Hotchkis camber links or anything for the front. I agree also, but if the drop is significant and I'm not saying 2" maybe less. I would get them and maybe a crash bolt of your desired range of adjustment for the front. Just because the alignment process is also very important in your car handling to the very best.
Tires and wheels is also very very important, but I wont comment on that either.