I would look for some good diesel shops in your area, best prices are usualy the little shops in the backs of industrial estates that no one has heard of. Get in the chat with some local mechanics etc...
Take them out yourself and take them in, will reduce the cost a bit. Cover the fuel lines and injector sockets with some tape or something to stop contamination etc. as soon as they come out. Refit with new washers etc. and a little bit of copper grease on the bolt threads etc...