im a gamer and also a dev. new 27" iMac help!

im a gamer and also a dev, so im going to get the new 27" iMac with AMD Radeon R9 M395 with 2GB, will the new GFX card be powerfull enough for the latest games .? and also will i be able to use the Oculus Rift on the new iMAC.?

Also, ill be wanting to sell my old 27" iMac from 2011. how is the best way to format the drive, and the hidden drives.?

Thanks in advance! 🙂