05 5.3 castech head issue, advice in replacing where what & everything

[stlucas]

05 gmc sierra quad cab z71 5.3  109,000 miles Coolant leak from damn castech 706 heads. I’m going to be replacing since i’ve had this truck since new & low mileage. Anyone have any recommendations on where to purchase an good set of new complete heads, an complete kit, Im thinking replace everything, heads rockers lifters, possibly even the cam. While i got it torn down what else should be replaced & purchased? Also any good links to get all the details for repairs torque specs etc. thanks