You will need to get both ancillaries for the 1UZ. Also, you will need to make sure that you get ancillaries for the particluar car/engine combo. Eg. there are two different Soarer "incarnations" of the 1UZ...one has two ancillary belts, the other one, and they AREN'T interchangeable. I'd suggest the Crowns are different again.
My suggestion would be to look for something that is complete with ancillaries...