The problem you'll run into right now is while the Aviator and Mix Master actually sound decent compared to probably the rest of the Skullcandy stock, they can be had for much less in locations other than the Skullcandy Website. I got my Mix Master for 120 at Best Buy, compared to the 300 the site charges for it. The Aviator is a decent headphone from what I remember, I haven't listened to mine in quite awhile, the Mix Master more so. My tastes prefer the Onkyo however. I haven't gotten to listen to the HF version, but I have the FC version and think its a fantastic headphone for the cost. From what I remember, the Aviator does have a similar sound sig as the Onkyo tho, so if its something you have enough credit with Skullcandy to get, you very well may enjoy it. I do remember that it won't have massive amounts of bass tho.
Sorry that I'm having to go off of memory, mine's been loaned to a friend for en extended period, she loves the look and the sound. If I remember there is a gaming headphone guide on Head Fi that actually had something good to say about either the Slyr or Plyr, can't remember which, but I believe it was the Slyr. You might want to research that one as well to see if it will suit your needs.
BTW, as far as the Onkyo cables are concerned, I believe the connection type for them is called MMCX which is shared by Shure. There are quite a bit of aftermarket cables out there that could work, but I do not have any first hand experience with them. I think Fiio has one that runs 35 or so, but the last time I checked for it it was pretty much sold out everywhere.