When I was looking at one bedrooms I checked out some studios as well. I found a nice one that was all-inclusive for a good price, but it didn't have a full kitchen, just a couple of burners but no oven, so that killed the deal.
If you're living there alone the no walls shouldn't be that big of a problem, look into getting some bookcases, room dividers, large dressers/closets, that would help separate your living room from bedroom or kitchen. Certain items could serve a dual purpose as well, a dining room table could easily be your desk or workstation. I wouldn't recommend using a futon as your couch and bed, but if you're cramped on space you could look into that, or a convertible sofa.
Look online at apartment design websites, look through an IKEA catalog, try to get ideas about how to use your space efficiently and maximize what you have.