Where to find/ how to make a platform type of bed?

So pretty much ive been coming up with new ideas for a bedroom and decided that what i really want to have is in the middle of the room have a level change about 2 1/2 or so feet. I pretty much just want like a platform bed only one thats a little wider and longer so that i can have my bed and a nightstand on it. I was wondering if there is any place that sells them or if anyone knows a way to make them. All i really want is a wooden platform thats sturdy enough to support a couple of people, a matress a dresser, and possible other little trinkets. Thanks :)