Methods and apparatus for coating processing reactor component parts are provided herein. In some embodiments, a part coating reactor includes: a lower body and a lid assembly that together define and enclose an interior volume; one or more heaters disposed in the lid assembly; one or more coolant channels disposed in the lid assembly to flow a heat transfer medium therethrough; a plurality of gas passages disposed through the lid assembly to facilitate providing one or more gases to the interior volume, wherein the plurality of gas passages include a plurality of fluidly independent plenums disposed in the lid assembly; and one or more mounting brackets to facilitate coupling a workpiece to the lid assembly.