Right, quoting yourself looks really silly right now.
I once found an AKG K240DF in a store for cheap but I did not have the power source for it. I found a Philips CD690 and the problem was solved. After that I upgraded to a Philips CD751 for its much more pleasing sound and it can handle 600 ohm headphones. Next step is a DAC for my CD690 to find out what kind of a difference a DAC makes and if the difference is there I will enjoy it. I still use the CD690 for first listens with CDs, it sounds more tedious than fun and I still get all the detail.
Now you want an expensive headphone for gaming and music. Find a good headphone amplifier with plenty of power or split the budget for a second headphone which is cheap but has good soundstage, detail and a good low range which should not be too hard. With the money left you can build up a listening set up.
I never cared for gaming solutions for I am not an avid gamer.
Good luck...