Hi and welcome to Orchid Board
Can you post a picture of the Den. That might help us advise on that one. Mine are not really doing much just either so I wouldn't worry too much. There is some culture info on Den. kingianum here if that helps.
Den kingianum
As for advise on what you should grow... well different orchids are easy in different parts of the world so it's difficult to give advise from over here in the UK. I get on well with both Phals and Den. phal hybrids but something different may be best in your part of the world.