Thanks a lot for all the input (and some critique regarding my request to have higher than 16 bit and 48 kHz)
As I see it, the downside with 16 bit DAC is that when you change the volume on the computer you will effectively reduce the number of bits used. Since sound is logarithmic you will easily end up using less than 12 bits at normal listening levels if you leave enough headroom to be able to drive high-impedance headphones. With a 24 bit DAC or a PGA (programmable gain amplifier linked to the volume control from the USB) you don't have to play at maximum volume to get at least 16 bits.
The benefit of using more than 48 kHz would not be hearable of course, but useful for measuring frequency response of headphones/speakers further down the road. Not a priority.
It seems that the PCM2707C is good choice if one wants I2S to a separate DAC, or another one PCM series with built in DAC. However no PGA as far as I can see, so you would need analog gain control via potentiometer and always run it on max volume in Windows.
I also found that it is important that the part name ends with "C", this is the newer versions that are supported in Vista and hopefully Win10 and forward, the other ones without the "C" are for XP and older due to driver compatibility etc.
Another better alternative is the AK4571 (thanks Buriedcode) due to built-in PGA it allows for volume control without loosing bits, AK also seems to have a lot more documentation and evaluation board circuit diagrams to learn from.
It can also be run without any external roms (unless you want to customize the vendor and product name that pops-up in Windows). Making it ideal for low profile project like this.
Some of the more high end options with 24 bit and 96+ kHz support, such as the XMOS series (built-in 32 bit, 8-core CPU, and more...) and even C-media chips (built-in microprocessor that require external ROMs) are probably a bit overkill for a hobby project like this. But definitely needed if you are building a 7.1 surround sound receiver with a bunch of DSP effects