NET

I wouldn't worry about keyword rich domains or EMDs (Exact Match Domains). It's content that ranks these days, not domain names.

I'd rather have a made up brand such as http://www.boohoo.com than something as limiting as http://www.buycheapdesignerwomensclothesonline.com

Your domain name doesn't even have to be relevant, if it did http://www.amazon.com would sell river trips and http://www.apple.com would sell fruit! It can even be personal, http://www.craigslist.com :)

If you have to choose a .org or net, go for the .org first.