My question is simply: Could you create a neon floodlighting bulb by just making a standard SOX bulb with no sodium in it? And how good or bad would this be compare to the actual cathode heated neon lamps?
It would be cool to just have some chinese SOX manufacturer make this if its feasible. 
Yes. You likely have to increase neon pressure significantly to avoid cathode sputtering and do not evacuate the outer bulb to avoid discharge tube to overheat. You will get a fun looking red lamp with kinda unpredictable lifetime. Also you may not get an optimum efficacy in red light because the relation between current density, gas pressure, tube diameter and light output is tricky.
If you want to play with custom made gas discharge lamps, cold cathode is a way to go. The technology is robust enough to make working lamps at home if you sink enough money into the equipment, and parts like glass tubes and electrodes (even large 90+ mA ones) are fortunately still available for purchase. Or you can just hire a neon glassblower to make just whatever tube you want
Much fun and not at all expensive.
Most truck manufacturers put more stuff, bell and whistle in the cab, but not much of the bed.
