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you need EMT Conduit equal to the distance from the kitchen box to the outdoor sockets except where you run through and enclosed wall. The proper protective weatherproof cover for the sockets you are going to add. and possibly a larger replacement breaker since you will be pulling more amps to the sockets through the original kitchen socket.
Also the couplings that match with the outdoor switch boxes and size of EMT, which you will probably only need 1/2" EMT.
You will also nee wire nuts to connect to existing cable from kitchen outlet and to jumper off to any additional outlets. Of course if you are hiring an electrician he should have all the material he need on hand if he is worth anything. If you have the sockets and the boxes to install them in you should be good and set up.