I have that combo and I love the sound of them together.
yeah i heard the battery life on the htc one is terrible. That was one of the reasons why i was going to get an htc one and an iPod!
You need to install the HTC Sync Manager. It easily copies your itunes library as it is.
Check out these -- and use any wired phone you like:
I just got one to put in car for aptX bluetooth, and it is quite good. Seems much cleaner than the Samsung version. Higher output too. If you want to make calls, you can get the Samsung HS3000 and use nice wired phones.