Do you have a spring shop locally to you ?If not talk to
http://www.denverspringandsuspension.com/ they have custom made me springs in the past.If they can't do it
http://offroaddesign.com/ can do it also.I would have custom springs made or grab 1 ton springs.As far as the rear end if it came out your trucks body style it might just bolt in.If you want a later rear end moving the spring perches and shock mounts are in order.Its just cutting and welding tho.