Where can I find somewhere which sells flutes of different brands?

You can go to Brook Mays, they have a variety of instruments and different brands. That's where I got my clarinet.

Fluteworld.com is a great resource. You can try out their flutes for only the cost of shipping. It is really worht it if you are in the market for a higher end flute, but not so much if youare looking for $500 and under.

Try a local music store as a reference to what you want and then buy it on e-Bay where it's cheaper. A friend purchased a Gemeindhart (I may have spelled it wrong) worth $400 for $250 as it was a music store going out of business. What a gorgeous instrument!!!!