My fiance wore a nice creme coloured Junaid Jamshed shalwar suit, with a shawl going over his shoulders. (If thats what they’re called) He looked great 
Shalwar suits are nice for Nikah for the groom. He gets to wear a suit any other time, because its his wedding, tell him to look a little different if he doesn’t do kurta shalwars to often. Men look great in Pakistani clothing I find. And its simple to.