*EDIT* 8/30/08
I obtained a used 25mm Tribeca Front Sway Bar for $50 (including some "modified" tribeca 25mm ID bushings that fit the Legacy mounting brackets).
The bar usually goes for about $80 at the dealer, so it's cheap for anyone even if ya can't find a used one (suprised that I did actually!). Other folks have determined that this 25mm bar acts like a 22.5mm as the outer arms are a bit longer than most stock and aftermarket bars.
Anyway - I had the bar installed in 45min total. It fits right in, but has a different route around the tie-rod - it goes over instead of under like the stock bar. There are install tutorials around so I won't go into all that.

I already had Whiteline end links F&R, as well as 2.5RS springs (1" drop and 10/15% stiffer), GR2's, and Grp N F top-hats. I also have TiC fender braces, a Cusco F strut bar, and rear sub-frame lock bolts to help hold the chassis together.
This BIG ass bar really compliments the other suyspension bits. I'll be adding an adjustable 20/22/24 RSB in the future to further refine things but this is GOOD for now.
PN: 20401XA00A at your local stealership.
-Chad