[holben]

Looks like they've got you on the right track. You will most definitely want a rear anti-sway bar to counter the body roll that is increased when you raise the upper control arm rear mounting point (center of the car). The 8.5" 10-bolt that was made for these cars in the mid-eighties by Buick is a very strong piece with a spool and axles. Since you already have the 12 bolt I'll stop right there.
Good luck with your project.
Don