Wine Storage Experiences/Advice

First, thanks in advance to any an all for offering their experiences/advice on home wine storage. I finally have space, about 100 square feet, where I can set up a racking system and ideally a "cellar-unit" too for temperature and humidity control. My "small" collection is about 200 bottles at the moment; probably half of which need or wouldn't be harmed from some extra time to develop. What cellar-units have you used or encountered; good and bad? While a decorative or a furniture-esque finish is not important to me, a good value is important. Self assembly is not a problem. Any cellar-unit suggestions would need to accommodate champagne bottles and a few 1.5L bottles. If local matters, I'm in the southeast USA. Thanks again. Jack