First the Houzz search box: put something like "split level update" in the box, then click on "Ideabooks" and then later on "photos." This is a project that has been done time and time again--beautifully. Also, I always think the interior designer Sarah Richardson does this well, so find her website and enjoy all her pics. You can do the staircase remodel in bits--one level now and the other level when the budget allows. But have a plan. This is a great time to call in an interior designer, even if just for a consultation.