I have successfully reduced 200lbs off my SC400 from stock and would like to share..
1) Alluminum light weight Rims and tires 50lbs reduction off stock..
2) Eiback springs and shocks 10lbs
3) 10 changer CD, spare tire and jack removal 75lbs
4) Deletion of hydro pump, fluid, cooler, pipes 30lbs
5) Optima battery 10lbs...
6) Underbody weather crap and covers 10lbs
7) Inside Door paneling 10lbs
8) I went from 225lbs down to 195lbs with proper dieting and excersize He He..
I think taking out the "strengthening center bar" (side intrusion bar) is a very bad idea Jibby. Toyota put it there for a reason mate