This is a Canadian site, but tristan threads is a great source of aurifil thread

http://www.tristan.bc.ca/cart/home.php?cat=27

I buy all my threads there and some embroidery stuff also...

http://pumpkinvinecorner.com/index.htm

The site has very good prices for Aurifil cones & spools. Also, check out the variety of hangers for small projects. Shipping is reasonable too.

I have this set:http://www.tristan.bc.ca/cart/produc...&cat=27&page=1 and this set: http://www.tristan.bc.ca/cart/produc...&cat=27&page=1 (I have no idea why red thread?) and about all the grab bags of the Aurifil. I don't care for the Aurilux thread for machine quilting but it may be best for embroidery work. I also have the big cone of Genziana Cotton Mako 50 wt from Cucirini Tre Stelle to compare to Aurifil. I can't tell any difference between the two.

The only place I have found to purchase Aurifil cones is www.allthatthread.com.
They are reliable, fast and carry many, many colors.