I have found that the full-coverage wigs tend to be the big hairstyles. That gets too hot in the summer!
I switched to toppers because they cover the top, but are available in lengths like 21 inches. The crown is an open weft, so they breathe. The hair is not as thick because they are designed to fit over your natural hair and blend with it. (See my profile pic).
They have a variety of colors and styles. Most of mine are Raquel Welch brand, which can be pricey. The other downside is matching the color to your natural color. For me, it was easier to dye my hair to match the topper. That way, I got the color and style I wanted.
Of course, price is a consideration. If you go too cheap, the wig will look cheap. However, going expensive does not give better results. Some expensive wigs are overpriced without a huge jump in quality.
My suggestion is to visit a wig store. Nobody there will question why you want a wig. It could be a costume party, Halloween, CDing, or daily wear. They don't care. They will measure you for the right size. You can get good feedback about colors and styles that fit you. If you don't like something, tell them so they can adjust. Wig stores have a lot of brands, colors, and styles in stock, and they can help you decide and, more importantly, help you learn about what will work and what doesn't. You can always then take that information and shop online for deals after that.
