You could use (maybe ????) small wide flanges or perhaps cold-formed steel studs but you really should have someone knowledgable take a look at it and design it for you.  There would be a lot of liability involved if it falls in on a family.  Also check ceiling grid systems.  In order to use a ceiling grid system you will have to be able to support the grid from above structural members.  A professional must check that.  The grid hangs from members above that must take the weight.  Grids do not support additional loads beyond drywall and maybe some very small lighting fixtures.  Again you would need a knowledgable professional with those systems.  Ceiling grids typically are about 1.5" tall so that might save you more room.  USG and Armstrong are two manufacturers.

Other than really general ideas we can't do much else for you.  These are some possible ideas, but you must have a professional familiar with the design of ceiling members help you with it.

Thanks for the reply.

Can you tell me where I could find such a professional familiar with the disign of ceiling members?

I would just look in the phone book for a structural engineer and ask him/her about it.  A dry wall contractor might be able to help you also.  A lot of times they have professionals they use and could help you or perhaps even give you a bid to do the work.