Okay more research here i was pointed in the direction of Bilstein which i will use.My question is can i use the 5100 series up fron and the 5150 series in the back?

Okay where can i buy those National spring packs i have done a search and did not find anything on where to buy them anyone have the addy to their site?

www.spencerlowracing.com has Nationals I believe.

www.4x4parts.com has Ranchos.

There were some reports about the SLR ones sagging under full load. I don't know if that has been fixed. Maybe OffroadX has some info on that.

The 4x4parts ones are a 12-leaf because of 2 load leafs. I tossed those for better clearance and haven't had any problems. Now if you're going to get a 10-leaf spring pack and are going offroad you really should get Darlingtron leaf skids. They bring your rear clearance back up to stock and protect your shock mounts.

You can see the leafs and the skids in this photo. Articulation is great.
http://www.xterra4x4.com/Trips/Moab2002/GoldBar/pictures/tiltdown_lege.jpg

Okay thanks might go with the Darlington's then okay your using Bilstein's ? If so are you using just 10% or 20 % on the back to help with the new bumper carrier.

Yup, just came across an old post today somewhere that remarked that the SLR pack wasn't up to anything but stock load duty. Carrying around a bunch of gear all the time or a rear swingaway bumper didn't agree with it and it sagged.