I went to a wedding where the groom was beige with hint of gold coloured Kameez with sophisticated embroidery around the neckline, and white Shalwar, and the phoolon wala haar made him look like a perfect dhulha. I thought that looked quite nice.
personally i like the sherwani look on the nikkah day...it looks nice...but if he wants to wear a tux or suit let him...otherwise hes not going to feel comfortable and look awkward. if he goes for a suit maybe if he co ordinates his outfit to urs in some way...and about him standing out. its not like people arent going to know hes the groom :)
mehndi id say....a smart-ish shalwar kameez/kurta...? and then nikkah day sherwani/suit and walima a suit defo
Usually guys wear Kurta shalwar on Mehndi's, Shalwar kaameez on nikkah if its on a different day from barat.
Barat day- Sherwani, Suit with vest or Tux.
Valima day- Suit.
I personally have seen a lot of guys wearing suit on shadi day. My husband also was not a fan of Sherwani, so he wore a Black suit with a Black vest and very light gold tinted shirt with tie matching colored to my dress. With the Garlands he looked like a Groom,
however one of his single friends wore a groom like sherwani(pretty weird) and the people that didn't really knew who the groom was congratulated him while he was on the stage with my hubby. LOL
I think its better to go with what ever the Groom prefers after all he is the one who has to wear it.