front and rear strut tower bars will help with flex a little, but aren't a substitute for a straight chassis. you might also look into some of the Do-Luck stuff that is out there. they make a replacement subframe, floor braces and the like.

 

How about the Cusco X-brace? That should stiffen things up a bit.

 

bushings: either the groupN bushing kit, or new laterel links and trailing arms with upgraded bushings (whiteline, noltec, sti, cusco). STi engine & tranny mounts. ALK's (whiteline or perrin) or STi front control arm bushings.

front strut bar is pretty much for looks, but the rear may help a bit. It should be last on your agenda IMO.

that cusco sub frame brace v2 as stated above is a good call as well.

How do you like the larger front swaybar/rear swaybar combo?

 

not to hijack the thread here, but on a car with well sorted suspension, the strut tower braces actually make a noticeable differance. i installed the front one a month or so ago, and noticed a small differance. i installed my rear brace the other night, and have already noticed a significant differance. if you're running STi takeoffs or coilovers, you'll notice the change. i think that the increased chassis rigidity in the rear gives me a better feel for what the rear end is up to. i drive a sedan, but due to the wagon's design the rear bar will have more of an impact on it than a sedan.

as far other suspension improvements (that don't stiffen the structural elements of the chassis) go, i'd also reccomend solid front endlinks with either pillowball bushes or hardened urethane. i found that it sharpened up the feel at the front end when i installed my Noltec front end links.

 

I don't mean to be an asshat, but I would have told the ins. co to take a flying ****, and had it totaled. Mileage or no, a car with major frame damage makes a good rally car or track car...not a daily driver.
Tell the ins. co that you want them to buy you a new car and you won't take 'NO' for an answer. Get a lawyer. Get a new car, that's what you insurance IS FOR....getting you a new car if yours is totaled and yours was.