Hey jspec_racing,
The stock sway bars on my 1999 V6 were 17mm front, 16mm rear.
I installed a Whiteline set: 24mm front, 20mm rear.
If you picked up a TRD rear, it is a 19mm adjustable.
The inner most setting is about 21mm stiffness.
If you were looking at Intrax or Addco, they are 22mm front, 19mm rear
Here are the Whiteline US distributors I know of:
http://www.globalperformanceparts.com
http://www.185performance.com/cgi-bin/performance/
http://www.ctmotorsport.com
I have purchased 2 sets of the Whiteline from 185. (Put a set on an ES300)
I always dealt with Josh at 185.
Gom
A few pics of the Whiteline