i doubt you'll find a "refurb kit" as such, there'll be gasket kits possibly in two flavours, "top end" or "full" or you can buy individual gaskets
big end and mains shells will depend on if the crank has/has not or needs to be reground which means shells and thrust bearing sizes to suit
rings and/or pistons will depend on if it has or needs to be rebored, again requiring sizes to suit, if rings only it'll require glaze busting anyway
heads can need all kind of jobs so i usually farm those out and have them professionally refurbed/checked over
injection pump requires specialist tools to refurb as does the injectors
"your" job mostly consists of disassembly and reassembly of components (do not take the injectors and pump to bits as the reconditioner might start laughing), then deciding if certain parts need replacing/reconditioning etc'
hope that helps