Daniel, we certainly recognize the bed, as it's the very same Modernica Case Study model sitting in our apartment. The bed does come with a headboard, and there are options for wood or steel hairpin legs, with an assortment of finishes. In regards to your DIY sourcing requests, we have a few under the jump... If you're handy enough, perhaps you could put together your own platform bed with some hairpin legs from Hairpinlegs.com. Taking a look at our own Modernica model, we note the platform itself is not just a flat solid platform, but has a perforated metal mesh grid work to let the mattress breathe.
Other ideas include forgoing the hairpin setup and creating one with storage underneath like these: