How do you decorate your place, what kind of style, colors, and feelings? That will greatly influence the type of door you might want. Also, think of your budget, and whether you want to install it yourself or hire a professional (you don't need to tell us, just keep that in mind). Then look around Houzz, in the products page, they have lots of interior sliding doors and hinged ones, from elegant frosted glass in a dark wood frame, to rustic reclaimed wood planks. You may not want to purchase that exact model, but it might give you a better idea of what would fulfill your airflow needs without sacrificing style.

Thank you Groveraxle for the virtual ! you are too good a designer that is why I cannot help troubling you ;) you have your biggest fan in me ever since your first advice:)) As for an in-house designer I am certainly going to call somebody soon . Just that I get such a lot of options and great advice from highly accomplished and talented Houzz designers ..I would be better prepared after these conversations ..please forgive me for pestering you guys like this:)

example: winding staircase, source internet Little modification need to be done for entrance lobby opening, where you could accommodate a shoe rack and the complementary vertical wall can act as a amazing entrance decor wall wall in Kerala style heavy color play or texture/wall cladding with brass mural.. by doing this you get space to mount TV unit and a good space for sofa arrangement (make sure sofas are light as the space is less to accommodate baggy sofas), staircase can be made in the shape shown in sketch plan, with marble finish on the foot steps (or as per interiors), space in the bottom of staircase next to master bedroom wall can be utilized for chest of drawers or a tall furniture, make sure the staircase bottom part to be casted smooth in finish.

Just because you want to use the space below the stairs, do not just add drawers or shelfs unless you reaalllyyy need it. I would suggest go for adding something green to your house. Its healthy by adding air purifying plants. These plants are nowadays available in most of the nurseries and moreover Green patch in the house gives a beautiful look to the house and is also good for eyes ( the green color). Below are few picture to motivate you for Green patch or Indoor garden.