Renewing the inlet and exhaust valves when overhauling the cylinder head is desirable. New ones will ensure good sealing, if the seat is lapped in correctly.
You will also require new valve springs, valve-stem-seals, collets, spring-seats and many other related parts to help ensure the valve gear delivers perfect performance and remains durable when the engine is worked hard. Mixing new parts with older worn items is best avoided. Consider also a new cam-shaft, rockers and rocker-shafts if the old ones have become worn or damaged?
Other related parts you may wish to consider: