Newbie HiFi Headphone & Amp pairing suggestions

Hi Gang,

I know headphones and headphone amp pairings are very subjective and vary person to person. Being new to the HiFi world of headphones, I've narrowed down (I think) a new headphone purchase to:

• Audeze LCD-X
• HiFiman Arya
• Sennheiser HD800S

I've not had open ear headphones before but have a relatively quiet office in the house (when the kids aren't around) and am excited to explore the HiFi headphone world. 

So, I'm curious if any of you have had any experience with the above and would make any recos either way and if so, what amp you reco pairing with it. I have a buddy who has the Viiolectric V281 and swears by it but it seems impossible to find (and quite pricey).

Lastly, is there any hope of getting a great DAC and headphone amp in the same unit or would you reco separates for longevity's sake?

I should mention that this is all really for my home office desk setup. So can't fit mega huge gear on this desk. Appreciate any recos!
I recently entered the HeadFi world myself. My goal was to replicate as much as possible the sound characteristics I love about my big rig, which include; clean and detailed yet natural treble, excellent imaging and soundstage, disappear as a sound source, and overall neutrality with good tone and balanced bass. After reading many reviews I ended up with Hifiman HE400S headphones driven by an Audioquest Dragonfly Red, and I was surprised how much I got of what I was looking for. I’m finding the headphone experience to be very fun and rewarding in its own way.

If this at all sounds like what you’re looking for I’d strongly consider the Aryas. They do require some power, but I think something like the Singxer SDA-2 DAC/Amp would pair really well with them and costs under $700.  Just saw the guy at audiophile-heaven review site just reviewed the SDA-2 and the Aryas were one of the ‘phones he used during the review so might be worth reading.  Haven’t heard the others you listed so can’t really help there, but hope this at least gives you something to go on and best of luck in your search.
I don't think you would go wrong with any of the headphones you're considering.  I have not heard the exact models you are considering, but have LCD-XC (closed back version of LCD-X), Hifiman HE-560, and Sennheiser HD800 (not HD800s).  Audeze and Hifiman have a fairly similar sound signature, with Audeze being just a little warmer and maybe a little better in the bass department.  The HD800 is a very "clinical" headphone, not really bright, but they can be too detailed for some.  From what I've read, that was tamed down a bit in the HD800s.

So the first thing you have to consider is what kind of sound signature you like.  

Then you need to think about things like comfort and amplification.  Some of the Hifiman headphones can be pretty hard to drive, the HE-560s are.  The HD800 is lighter and more comfortable to me than any of my Audeze or Hifiman headphones.

If you want to put together a really nice rig, take a look at Sony - MDR-Z1R headphones and the TAZH1ES amp.