There's a member here selling the same front disc package for $650 and it includes MORE than that PST disc kit. The PST suspension kits are decent from what others have said, but I've not used them so cannot comment directly.
I just did a disc swap and cheaped out. Performance online offers a front disc kit for $400, but then it was another $80 for lower ball joints, the dust shields don't fit right, the included hoses don't fit the A body brake line brackets, there's no hardware included for the lower ball joints (another $30 in grade 8 hardware that takes up more space than the factory parts). I'm nearly done, but wish I had bought one of the packages a member has listed here instead - would have been more inclusive and had all the proper hardware!
You'll also need either new upper control arms (and upper ball joints) or upper balljoint adapters like Dr. Diff sells - this is regardless of what kit you purchase. Earlier A bodies had smaller upper ball joints and the large ones don't fit the small jointed arms.
I'd go with what's listed on this site first. Known quantity and more of the difficult parts already sourced. A master cylinder can be picked up anywhere for reasonable coin.