ITM import block kits...
I see one for a vg30e for my truck for $353.06,includes...
pistons,rings,rod bearings(no rod or crank though in this kit) main bearings,thrust washers(if required) oil pump,and a full gasket set.
I didnt see one for the vg30i but I'm sure they have one since they have ones for both the z24,and z24e truck 4 banger as well.Theres another company that has rebuild kits with over size pistons but I dont know there name,but there sold out of Northern auto parts(a catalog)