Wow thank you!! Super helpful post and gives me a lot to think about.
I would like to get the Q701 but having to get an extra amp is a bitter of a bother for me, I checked out the Fidelio X1 and they are definitely my favourite and reviews are all superb.
My main use would probably be for immersive gaming, but would also be nice to hear footsteps in COD. Music is not a priority but would also be used for Netflix or movie watching when the girlfriend is sleeping.
if you watch movies and netflix through your consoles then you could just use the mixamp for the headphones that you choose.
if you use a laptop it would require a dac (laptops as well as onboard audio tend to have really crap DAC's built in) as well as a amp if your thinking of Q701's. if you use a phone/tablet and it's made by a decent company like Samsung then it should have a decent DAC built in tbh so all you would need is a amp to power them, it's just a really messy situation tbh needing other devices, etc.
the thing with amp/dac's is there isn't much difference between the cheap ones and any of the more expensive ones under say £200, that's why a xonar DG for £15-£20 is recommended to anyone using a PC with headphones if they want something better then they really need to stump up top money for a noticeable difference £200+.
tbh I think Fidelio X1 is the one for you (doesn't need an amp with anything) if you want to use it with your pc get a xonar DG for £20. use with consoles then get a mixamp (5.8 mixamp is wireless and only available second hand, all other mixamps are wired and newer).
now that we have the sources sorted and headphones (fidelio X1) all you need now is a mic.
there are 3 options:
V Moda Boom Pro
http://v-moda.com/boompro-microphone/
it's not cheap but it's crystal clear, replaces the stock wire on the fidelio x1's to give you a brilliant simple solution which means one less wire to worry about.
DX Clip on mic
http://www.dx.com/p/mini-clip-on-microphone-7080#.U3vyifldV8E
£1.48 currently (I paid £1.56), this mic is pretty much the one to get if you don't want a v moda boom pro, don't be fooled by it's cheap price it's better than the next option, the only downside is that it's coming direct from china so it will take about 1-2 weeks for delivery. I actually use this mic and it's brilliant and costs less than a soft drink in a restaurant, cannot grumble with that.
Speedlink Spes Clip-On Microphone
http://www.amazon.co.uk/Speedlink-I...F8&qid=1400632170&sr=8-1&keywords=clip+on+mic
this is what you buy if you need a mic straight away and cannot afford the boom pro, it's slightly worse than the dx mic as well as more expensive but you should get it within 2 days of ordering.
also to note some people prefer to replace the stock cable of the fidelio x1 when using it for movies/music as the stock ones have a high resistance for some reason, some people like the stock others don't so it's worth buying another and comparing the two just to see if you can notice a difference, it's minimal but it should be there.
the best one to go for is one of these
http://www.amazon.co.uk/KabelDirekt...=1400632392&sr=8-2&keywords=kabeldirekt+3.5mm
it comes in various sizes from 0.5m to 5m
no point in buying a more expensive cable as to get an even more noticeable difference your talking about dropping £35+ on a cable just to get a very small performance increase. kabledirekt cables for less than £5 are the best option for price to performance.
so to sum that all up you need to buy a mixamp (for consoles), toslink splitter (to plug both consoles into and then into mixamp), 3 toslink cables (kabledirekt), fidelio x1's, whatever mic you want and a replacement cable for your X1 for a slight performance increase, also possibly a xonar dg to replace your onboard sound on your pc if you wish to use with your pc.
also the best amp to get for the money is the topping nx1 it's about £22 on ebay and better than fiio e11 which is £54 on amazon.
i have sent you a flubit invite in your trust (that will get you a discount on anything you buy from amazon).