I'm looking for a cheaper alternative of the FTDI chip to add USB support to an MCU, so far I like the PL-2303HX however the problem with it is there are fake copies all over the net. And I don't see any official distributors that allow you to buy original chips online.

Does anybody have an idea where can this chip be bought? :) Preferably from some trusted distributor, as ebay is full of the fake copies.

Or can you recommend any other lower cost alternative?

If I use an MCU with built-in USB (like this one by Atmel) is this a good choice? Do I need any windows drivers in this case?