Have a look at Pickle Player. It uses a Flash MP3 player with HTML5 <audio> fallback for non-flash supporting devices like iPhone/iPad/iTouch.
With customizable player skins
Thanks for your help!
The two solutions look great and it seems there are options for playing two audio files simultaneously and then just toggle mute between the two to get that A/B comparison effect. I have to look into the two players to see if that will really work as I imagine it, but at this point I am confident to find a solution.
I really like the idea of the players switching between HTML5 and Flash, depending on the capabilities of the browser used.
@Nancy: Pickle Player looks promising and the skins look usable and pretty stylish as well.
@Marian: jPlayer looks stunning, especially the big button version with the round progress bar, very much like the iTunes preview player, I am loving it!
Thanks again, you saved my day!