Salam,is wishing with "sabahul khar,sabahulnoor" Islamic.it is said these wishes r connected with gods of preislamic and our beloved prophet promoted only Salam.
I don't see neither I've read any Harm in saying those words,however if your heart is not satisfied using those words avoid them and use Assalamu Alaikum instead.Allah Knows best... Waalikum Assalaam