Where do I start

I am a vinyl guy.  And really new to this kind of stuff. Recently I have been working from home quite a bit.  Enough so, that I had to stake out space in my home to create an office dedicated to just me and not the rest of the family.  A golden opportunity to try something new.  So, I have decided to create a modest desktop system.  Speakers will most likely be Omega Super 3i (I have a big desk).  I have a host of amplifiers that I could potentially put into play, including Clones 25i, Miniwatt N3, and ASL Tulip 2a3 (really sweet but not desktop ready; would also require a dac with some sort of volume control).  I also, have an iPad, iPod, and Surface 3.  As well as an AppleTv and iMac G5 in other parts of the house.  The laptop I use for work was issued by the company I work for, so I can't consider using it in the mix. I have no idea what the best course of action is.  Can I use the Surface 3 as a Music Server?  Do I utilize the iPad or iPod?  What kind of dac do I need (willing to pay $500 to start and get my feet wet) --of course upgrade in the future if I really get into it.  I will essentially be building a new music library -- my wife thinks my music is stale (read I am getting old) and this would be an opportunity to try some new things. Don't know where to start.  I read some things about using the ipod into a pure i20 (maybe upgrading the power supply) -- but I don't want to go that route without fully considering my options. I would also like to take the time to put my best foot forward in this effort and not just aimlessly experiment.  Your thoughts and suggestions are much appreciated.
Instead of archiving a library I suggest a Streaming Service such as Pandora or Tidal.From USB out to outboard DAC.If you don't have a problem with Chinese gear I HIGHLY recommend the SABRE DAC2 from HiFiMeDIY.Better than most $500.00 DACs,less than $100.00 Delivered..From DAC to amp & speakers...A streaming service will expose you to a ton of artists you never new existed.You can also utilize the co.laptop without worry since you are not storing anything on it.Head-Fi.org is a great place for equipment reviews.Good luck...
Hello gotog. Sorry for the delayed answer.

I suggest going in small steps. I did that, and being a non-pc-techie I'm happy I did. Plus computer audio opens the door to maybe unimagined options. 

You don't need much computing power to play music. But using a dedicated computer allows you to turn off many programs, and features that induce electrical noise inside the computer, so it's the preferred method. If you can get a hold of an old laptop, even with Windows XP, that will do.
I see you have several Apple devices. I have iPods, iPad, iPhone, but no computer, so can't really talk about it. Some people swear about their Minis. Maybe buy a used one to get your feet wet?

For playback you need a software. I use JRiver Media Center and it's good. You can install JRemote on your iPod or iPad, which is an app to remotely control JRiver.

the key feature you want in your DAC is asynchronous USB. You will connect the DAC to the computer through USB. The computer is an electrically noisy environment, though, and the internal clock is all over the place. On the other hand, the internal clock of the DAC is in a very controlled environment meant to play back audio, and asynch USB forces the computer to use the DAC internal clock, reducing jitter. I've been off the DAC merry-go-round for a while now and don't keep up with all the news, but I'd say look into the iFi products to get your feet wet under the stated budget.

where will you store the music? One approach is to stream. Make sure you can get enough definition. 
If you wanted to digitize your CDs and play them back: I recommend dBpoweramp for ripping CDs onto a hard drive. And if posible try and avoid using a USB hard drive. The issue is USB stands for universal serial bus, so processes happen in series. If you are playing back audio real time to the DAC and in series you are accessing the data, well that's not optimal. It's not a deal breaker either! Initially I was doing that with my Win XP laptop.

PC playback is all I do now. I sold my CD player because I just wasn't using it anymore. I built a server designed for playing audio only (looks like just another audio component) without screen (I use JRemote in the iPad) no fans or hard drive motors, super optimized the software, and it's the best palyback I've had. I then tried a unique piece of software to run digital room correction and evntually was running digital crossovers and biamping my speakers, liberating my tube amps from having to reproduce the bass. I now find myself at the quandry where I'm realizing I'm getting better sound without my beloved Lamm pre in the chain. I'm heart-broken! I thought it would never leave my house. But my ears suggest otherwise...

I hope this helps