The remote that comes with the Transporter is indeed quite limiting, but if you really do want a Transporter, the Duet Controller, which is a touch screen remote control, will also control the Transporter.
Even so, I prefer using iTunes, a Mac (or PC), and an iPod Touch/iPhone. But that's me ...
The Macintosh in particular is known to deliver a good out-of-the-box experience with respect to outputting music to a USB DAC. No spurious white noise issues. Ever.
There's nothing wrong with a PC either, but because of the large number of different PCs being made out there with wildly different executions you'll find that your mileage may vary. For example, this thread shows you how some problems people have with their Dell laptops and USB audio.
http://www.audiocircle.com/index.php?topic=57482.0In this case, it's not a Windows problem (I have nothing against Windows), it just turns out that with so much choice in the PC world it's hard to know what's good without giving it a whirl. In the Macintosh world, there are only a few models out there and they're all good. It also turns out that iTunes on the Macintosh is quite good too.
The Bryston BDA-1 is a DAC only and it has USB input. The RWA Isabella is a preamp, and it also has an option for a built-in DAC. RWA also sells their DAC as a stand-alone unit called the Isabellina. If you do decide to consider a RWA product they do have a 30 day no questions asked return policy.
Other USB DACs to consider are made by Wavelength and Empirical Audio. When putting together my system, I also strongly considered the Wavelength Cosecant v3. Wavelength is of course very well regarded and has a long standing reputation. I especially like how the DAC board in the Cosecant is modular so you can swap in either an oversampling or a non-oversampling design.