Hire a professional (either architect, interior designer, or remodeler).

Bader, you showed us drawings, so have you hired someone to change the physical structure? Are you asking about interior decoration or are you asking about interior architecture?

For a modern feeling, you can juxtapose some of the oriental elements you have there with sleek Italian furniture. If you look at Minotti, B&B Italia, Poltroon Frau and Roche Bobois you might see some elements you like.

A mix of elements takes more thought, but accomplishes more that going with everything matching.

The most important thing to keep in mind is the need for everything to stay uncluttered, so be sure to have plenty of shelves and credenzas and such to store things in your basement.

Good luck with your project.