I have noticed some bonneville owners have a tower brace....where can I get one at

You don't have one? You're supposed to, and it'* terrible for your alignment not to have one. You can get a strut tower brace anywhere at a junkyard from any Bonneville, LeSabre, Park Avenue, Olds 88, 98, and possibly one more such car that I've missed.

http://www.zzperformance.com/products_img/626_1.jpg

I don't think we are talking about the same thing, I have only seen a handful of bonnies with this equipped

Yes, do you mean the rear struts? The one from ZZP is meant for W-bodies like the Grand Prix, Regal, Impala, etc. Bonnevilles are H-bodies and use different-length bars.. If you have a Bonneville from before 92, you probably don't have a strut bar. Here are some pictures.

I own a 00 booneville and don't have a tower brace.. I have been looking at many photos on cardomain and haven't found any that came with stock with one

I dont think 00+ came equipped with a tower brace. I know mine didnt.

what changed on the 92-99 bonnevilles in 1996 with the suspension? so the suspension on a 1995 ssei is different than a 1996 ssei? please explain!

I think the suspension may have changed, but it'* not likely. I just suggested the 96-99 because I assumed the electronics changed concerning ABS & such.

Where can I find this write up? (been look'n but can't find it)

I'd just like to reinforce the fact that lowered spring are not something you want to mess with unless you have a good amount of money ready. Not only will you need the springs themselves, but you'll need shocks to go along with them that can compensate for the additional rebound, possible anti-pogo washers like the GP'* need, and depending on the kind of struts your car has, you may need camber plates as your suspension geometry will change and your wheels will have undesirable camber angle when the spring is compressed, such as when taking hard turns.