I need a usb dac for my PC and to be used together with NuForce NE-600X IEM. I currently do not have an amp so I guess the setup will be: PC>DAC>IEM
 
also planning on using it with my phone (but I guess connectors can do that) 
 
hifimediy/stoner acoustics?

The hifimediy could work, but I personally found the highs on it to be a bit harsher than what I would like.  After owning a few dac/amps in the 100-200 dollar range, (magni/modi, hifimediy, AuneT1, audinst MX-1), I think that the best bang for your buck would be the MX1, which can be had for around 100-120 dollars used on the classifieds here.  It has a pretty decent dac on it and a fairly powerful built in amp.  The sound signature is a bit warm, but very smooth and enjoyable without any fatigue.  If you were going to go Modi or ODAC, you would need an external amp for them since those dacs don't have a headphone out.  The cost of the modi/odac will run you around 100 bucks + another 100 or so for a decent amp (magni/O2), and even then I find those setups only comparable to the audinst MX1.

At this price range FIIO E17 is unbeatable as a DAC/Amp.

In case XMOS+ES9018 I2S USB to fiber coaxial 192K-24BIT
 
149$ at ebay.
 
Unmatched in price / quality worldwide. It even has 2x TCXOs for internal master clock.
Its a very simple ES9018 implementation i would say but it seems to be not bad specially not for the price considering the ES9018 alone costs 60-70$.
 
ES9023 costs 2-4$ and is good but cant compete with the ES9018 in every aspect. For ES9023 i would buy the HifiMediy DAC for 50$. I got one and it has the same sound quality as the dragonfly 300$ (9023) which i owned for a week.
 
I wouldnt buy it cause my lately bad experience with a seller from Taiwan but if you take the risk to buy from asia this is as best as it can get for the price range.
 
No Amp needed for either ES9023 nor ES9018 anyway cause the output is so strong i can use it even with my DT880 600ohm headphones with more than enough headroom for the gain.