In the above images, the first and the last are part of the same door. I used silver pendants from an antique store to embellish the doors

Placement of Temple shall be such that you shall be facing towards East direction ideally! It will be better if you can share plan of your house marked with the directions to make suggestion on placement & space allocation!

pooja room should be depicted as traditional and ethnic, one can use wooden carved MDF sheets for paneling with duco paint as its finish. other option can be wooden square mesh panel with bells - photo attached for reference. POP niches can be made in dome shape with led lights. niches in the wall, reference picture

Try looking for the refurbished wooden doors, Madurai you will find some really intricate detailed wooden door. What i am assuming is your pooja room is separate space with a door. Keep the pooja room well lit and in white/blue color and let the door be carved and of antique style.