My Ford fiesta 1.4 diesel van head gasket?

My Ford fiesta 1.4 diesel van started over heating the other week I took it to the garage and they said that it's the head gasket so they want to put a second hand engine in it but I've herd of skimming the engine which is alot cheaper any opinions what to do?

They are looking for work. It's much less labour to take the head off and replace the gasket. The head does not always need skimming. A careful check has to be made with a true steel straight edge. Only if the head is seen to be warped does it need skimming. Ask for a quotation for a head gasket change only. Then take it to a Ford dealer and compare quotations. With an engine swap you could end up with a pile of junk under the bonnet.