Took be about 2.5 weeks to build this bed, working evenings and a couple full days on the weekend. I HIGHLY recommend getting a Kreg Jig. It made life so much easier.
To go from a queen to a king, simply add 16" to all of the width pieces. All of the length pieces will be the same for a queen and king.
I added one 2x2 support beam down the middle of the bed, with two 16 3/4 inch legs attached to it, for added support. I screwed the slats into all 3 of the 2x2 support beams.
The drawers are the trickiest part. Make sure you follow the plan in order, waiting to install the drawers until after you have screwed the storage bins to the headboard and footboard.