A 28 CU version would have to be a totally different design, something like the Intel/vega thing combining multiple chips. Without dedicated HBM or GDDR5 memory a 28 CU design will be extremely bandwidth starved.
Since I'm out of the EU you are basically saying that I might as well wait and buy through your web shop because that will yield me an automatic 25% discount and most likely be cheaper then through kickstarter. You see the problem.