I have a 2013 Toyota Avalon. I believe it is the same suspension set-up as the ES350. so wanted to share the outcome with you guys.
I used H&R Sport Springs kit for a 2012 and newer Toyota Camry. I know Tien and Eibach also make springs for this application. With H&R, you can use the 4cyl kit or 6cyl kit. Part numbers are different but the springs are exactly the same.
The reason you need to use the '12 and Newer kits are becuase the front passenger side spring is "wound" in the opposite direction of all the other springs. To make sure everything "seats" correctly, this would be the kit to use.
I also installed Staggered Zenetti Torinos. 20x8.5 with 245/35/20 in front and 20x10 with 275/30/20 in back. And they were able to get the alignment back to factory specs.
I apologize if I am way off base and your suspension is different, but wanted to share in case it was.
first picture is of the passenger side front spring "wound" the right way.