Welcome to the forum! As a recent MAC switcher (still have a few PC's up and running), I'd recommend that you use Max to transcode your FLAC's to ALAC's and use iTunes as a player on your MAC. I've done it and it was easy. Max retains all of the metadata. I still use FLAC while infront of a PC (which means that I have duplicates of my music library). Out of all the different music players for Mac, iTunes is the best IMHO. You could later on expand your iMac/iTunes setup with some AirportExpress and have your music wirelessly streamed to another room and set of speakers (remotely controlled by a iPhone or a iPod Touch). Once you're in the hands of Apple there's no way back 
I'd also recommend that you find some sort of tabletop monitor stands (or plinths) for your speakers so that you get rid of any nasty reflections caused by your desktop. You will notice the difference in sound quality

I'd also recommend that you find some sort of tabletop monitor stands (or plinths) for your speakers so that you get rid of any nasty reflections caused by your desktop. You will notice the difference in sound quality






















