"Akshay and Ash look terrific together. I am surprised that no one has thought of casting them as a romantic pair. They are outstanding, " Shah told.
Both Akshay and Aishwarya featured in 2004 movie "Khakee", but the actress was paired opposite Ajay Devgn in the movie.
Shah says his film shows a new side of Aishwarya who has done all kinds of movies including period movie "Jodhaa Akbar", action thriller "Dhoom 2" and real-life based drama "Provoked".
"'Action Replayy' is going to show a new side of Ash. She is playing a character which has lot of humour in it, something she has probably not done very often.
"She is in a retro look. She looks gorgeous in every look but no one has seen her in retro look. It's fantastic to see her in the new light. Again, it's a new way of looking at Akshay too, " said Shah.
He recently judged the acting and dancing skills of the Femina Miss India 2010 Bollywood Diva finalists and says some of the girls have potential to be good actors.
"There are a couple of girls, I have seen, are very good. I saw them for the first time so it's very early to judge them. They don't look like models, rather they look like actors.
They are still learning, but I could see some potential in them, " said the director who worked with former Miss World Priyanka Chopra in "Waqt - Race Against Time".
Asked if he thinks that Bollywood is the obvious next step after modelling, he said: "Miss India pageants have always shown interest in entering cinema and Indian cinema has welcomed them.
There are so many great stars coming out of Miss India pageants so there is a natural relation. But I doubt, whether every model can become an actor."
Some of the Miss India winners who made it big in Bollywood are Sushmita Sen, Aishwarya and Priyanka Chopra. But Shah says he can't imagine Aishwarya, who was crowned Miss World in 1994, as a model.
"Ash was model some century back. She has been actor for such a long time and has given such wonderful performances. I can't imagine Ash being a model, " said Shah.