Hawk (in any form) seems unlikely, certainly if the industrial (and export) opportunities are a genuine and serious consideration. It's had a damn good run, but it's reached the end of line, developmentally.
Some (UK built?) version of the Northrop Grumman / BAE T-X offering may be a possibility, I imagine. In which case, you'd maybe want to look at replacement of the Hawk 'legacy' & T2 fleet early for commonality (and you're gonna need a damn site more than ten aircraft to keep The Reds going for another forty years).
Shame AT2000 / Mako - HEAT didn't result in metal (composite, actually - or so I assume) being cut, though.
Please, please - just don't let it be some pathetic prop job in the form of the Tucano replacement....