Well it seems to have *most* of what you need. It doesn't include sway-bar drop links so those are extra (but $35 is a good price for them) and it DOES offer the option of either getting 3" rear blocks & an add-a leaf or 2" blocks with a whole new spring pack (that's the option I'D go with). It has the I-beam drop brackets which you need and the radius-arm drop brackets which I've seen plenty of bargain kits sold without. It says it comes with a pitman arm & since your truck already HAS one on there I can only assume that they're referring to a dropped pitman arm which is what you'd need with 6" but it would probably be safe to contact them & be sure this is what they mean (but I just can't imagine it being simply a replacement pitman arm, Rough Country is a pretty good name) and the $35 for the optional extended brake lines is also a good price.
So by my calculator (which is admittedly a $0.99 wal-mart special but it seems to add & subtract OK) it would be $580 for the 6" kit with the sway-bar drop links & extended brake lines for the front & rear. As far as I can tell the deal with the rear add-a-leaf OR whole new spring pack is optional and doesn't cost anything more whichever way you go.
Pretty damn slick. Used to be that all that stuff would pretty much run you twice that. Last time I priced out kits for one of the 80-96's it was $1200 for 6".
I was kinda hoping someone else would weigh in on this one, 80-96 trucks have never been my forte' (but with this 88' killing the grass in my front yard I guess I'm gonna hafta learn more about them if I want to use it to go out & tow home the 78/79 that I REALLY want). But to be honest this would be a good price on a straight-axle 78/79 kit so to get this price for an IFS truck seems pretty good.
OK, late edit. I just ck'd the Rough Country website & this is just the base price that *Rough Country* wants for the kits. After looking around the SkyJackers kits are running around $680 but those have huge rear lift blocks. The Rancho 4" kit is $1199. So yeah, it looks like a good price but I've got a bit too much going on right now to keep searching.