We have an 06 and although an earlier model, I haven't found much aftermarket off road support for the Sequoia. I have an ARB catalog and they show a front bumper and maybe some sliders, but that's about it. I have been looking into taking out the rear air ride springs and replacing with regular coils and even called Slee Off Road to see if they have done this- they said they haven't as the market is geared towards cruisers, 4runners, and Tacomas.
Hopefully, you'll have better luck.