I am building a website for someone who is starting a music studio. They want an mp3 player on there so people can hear some music. They also want the songs to have a download and buy link. I usually stay away from any flash stuff, but I think a flash player is the way to go for this right? Is there a good recommended one for this type of thing? I know there are millions out there, but I wanted to check around. Is there a good place that you can host/sell songs from that offers a customizable player also? Thank you.
The XSPF Web Music Player is a widely-used option. I've also had good luck with Flowplayer.
You should be warned, though, that if you intend for people to purchase your MP3s, they'll be able to see a URL to the MP3 location in the source you call to load a Flash-based player. From there it's only a few clicks to download the MP3 directly. Unless you're running a streaming server, which is significantly more work to set up.
If you'd like to avoid that, perhaps you should have 30-second MP3 samples of your songs.