Depends on how much you play, but seeing you are level 54 right now, you might make level 59 fairly soon. If so, wait for the chance to get the G20's. They will serve you well for a long time and at least until you can get the Burner 2.0's or until the higher level G20's come out.
I know this post is about irons, but a high-performance set of irons will truly shine with a good driver (I'd wait for the lvl 58 G20) and a better ball (even a medium performance ball like the Srixon would show considerably better playability than any of the WGT balls).