IMO the perfect phone for me would be the upcoming Nexus 5, but with a microSD slot. However, since I recently deleted all my music from my phone I can probably get by with just built-in storage (using Google Music All Access and Pandora).
I just want a nice large screen, LTE, no provider bloatware, good battery life, wifi N, and good Bluetooth support. I don't care about any of the "S" apps on my Galaxy S3 and none of the new features on the S4. I have my Galaxy S3 running Slim Bean and BMS kernel using Nova launcher
Personally, just using Google Music's free 20,000 song uploads I'm never in danger of bumping device storage limits. I've never been a fan of pandora, spotify, radio type apps. Also, the Google Music upload takes FLAC and plays back 320k on your Android devices. No need to maintain lossless directories separate I can't express how awesome the service is, but I guess it's not good for outside-US users. Don't recall it being available to all just yet, but I guess you can send invites
I agree with your phone choices, with the nod towards a possibility of 802.11ac