Suspension upgrades vs. Bolt in kits?

[Z11WEAVER]

I've been searching for info to do a nice handling aggressive static drop on a round body blazer. I purchased a 74 suare body 5 lug front set-up. My initial plans were to instal 2.5 CPP Drop spindles and 3" drop springs. Maybe even 3" drop spindles and 4" drop springs. Tech guy said I should also update to their tubular upper and lower control arms and ad a front sway bar. Then I saw the stance on a Porterbuilt level 2 kit, that has the stance that Im looking for. The bad, this kit is very expensive and requires different hinges, oil pan (for LS) and different or modified inner fenders. I'm trying to convince myself, this is the kit to pursue, but is a guy really making any improvements with this kit vs. the much cheaper factory style upgrades? I do like the idea of improved ground clearance with the Porterbuilt crossmember. FYI, Going to run 20x 8's up front. If I just go with the 74 set-up, are there any real advantages of the CPP tubular control arms other that the cool factor?