It seems to be Teak, which is a quite expensive wood. Lots of Yachts and Boats are made of Teak and it is used widely on decks, so, I still dont understand what your question is? What you are saying, is that because of the electrical and AC Vent, you need to drop the ceiling? Do you have straight walls/ceiling? can the wood be attached to the existing ceiling? The Carpenter installing the wood, could just lower the AC Vent and what kind of electrical are you talking about? The ceiling can lights?

you could always use any glass top table with steel frame and put a matt finished steel tray arranged with some metallic miniatures or candle stand or spray paint some wooden table with metallic paint and give an oxidised look.

You can use any seasoned natural hard wood like teak , sal wood etc. Another alternative is acacia wood (cost effective)!

HI Koushik. Depends on the style you would like to go with. Options are unlimited... Concrete flooring, Ceramic Tile, Terracotta Tiles, Clay Brick Tiles, Natural Stones, Natural Wood flooring, Artificial Grass (Cheap and Quick), Artificial Wooden Decking, Gravel etc.