rover 620 diesel

I've got the chance of swapping my 416 si (with k series engine)for a 620 diesel which needs new brake disks,question is ,is it difficult to replace the disks on this because the guy who has it at the moment was quoted £350 to do all four,i've done the front ones on my 416 and it only took an hour ,so are the 620's more difficult? also do the diesel rovers have the same head gasket probs as the k series engines or is there any common faults that i should look out for? tia