a) don't know
never heard of them
b) yes sways will make a big difference in body roll and cornering, not a waste of money.
c) people have done it before and I've heard them all say the front one is a major pain in the ass because you have to drop you engine cradle or something like that. I got mine installed by toyota so i dunno exactly.
d) Get Hotchkis Sways ... can't go wrong