Another lift kit question..

[1969k10stepside]

Ok,Im getting close to the part of my project where the lift kit goes on.My rear springs are junk so I am wanting to just get a lift kit with rear springs.I am leaning on going with a 4 inch lift and 35's for it.My question is which lift kit would be good for a swb 71 K10 in a 4 inch lift with all 4 new springs?It had a 6 inch lift on it but I thought it was a little to big for it.Where is the best place to buy them and how much does a lift kit with all 4 new springs usually cost?Does a 4 inch all spring lift have a shackel flip because I am leaning against that?Also do they require the spring hangers to moved?The lift that was on it required the rear hangers to be moved.The truck will be a D.D./ Garage Queen /off roader in its spare time.