The only thing I can think of that's close is a Lian-Li PC-A05B. It would need some modding though. http://kustompcs.co.uk/acatalog/info_1067.html The internal drive bays could be removed and some bondo and touch up paint could make the front smooth. Edit: I don't think it has a top fan. What are your aims and budget?
Maplin sell alu project boxes that are completely plain, you could probably do the minor mods that you require to get it to your spec.
will it be a little NAS box or something like it? desktop or tower? personally if you want that clean no drive look use some car filler and glue/fill the drive plates in and paint it. Would be far easier!
Does it actually need to not have drive bays or only look like it does? Silverstone have a nice line in "media cases" the LC19 is particulary sexy looking. http://www.silverstonetek.com/