What is the best way to play music with DAC/wireless?

Hello, I (an old fool just getting out from cd) have basic questions for digital format.

I have Aiff format songs stored in Mac/iPad/iPhone.
I play them by using app called Flacbox.

My question is, what is the best way to play these song?

1) DAC - Amp
This is my basic idea, for example, iPad/Macbook connected to DAC via USB cable then to amp.

2) DAC - Amp
Using USB thumb drive to DAC unit then to amp. Honestly I don’t know what advantages this method have over method #1

3) Streamer - Amp
Using Airplay from iPad/Mac wirelessly with Streamer then connect a streamer to amp via cable.

I do not want to pay any kind of subscription service (though it has a free version). I want my system to be closed one without internet connection. (Only using router)

For method #1 and 2, I consider ARC CD6 and PrimaLuna Evo 100 Dac. No idea what would work better.

For method #3, I have no idea what models are equivalent to models I mention above. (Good DAC with Airplay support) Most of them focus on streaming service that I do not want. Also not sure which one can work out the best with Airplay. (Only wireless solution that I can use free. I feel like airplay is still better than bluetooth.)

Please share experience and advice how I can get the best sound quality. Also if you have any model recommendation, please share some wisdom, especially airplay supporting one. 

Again Please feel free to educate me. Thank you.
It sounds like your system is what I want to set up. I also build up music storage with AIFF and want to use iPad as the remote. Since apple does not support Airport express anymore, I think I would start with apple tv path. Can I ask what kind of standalone DAC do you use? I read couple reviews that Bluesound node 2 is not an ideal solution. I was thinking about Lumin or something, but still not sure what would be most efficient way.
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I love the Exasound Sigma Streamer/e38 DAC combination. I stream my own music on a NAS, high Res music from a music subscription site, DSD, FLAC, etc. 
But from an iPad, all you need is Airplay. And it handles AirPlay plus room for expansion.