Wet room, and shower trap?
 

I am going to be installing a wet room, with a shower. Does anyone know somewhere cheap on line to by a convertor for a 150mm X 150 mm stainless steel tile grill to a shower trap?

Is a gully trap with a 75mm seal, a 50mm outlet and a 150mm X 150mm tile grill ok?

Im fine with everything else, just need advice on the trap/convertor/tile grill?

Thanks