Replacing NPN Transistors that failed with similar/better?
Only the designer of the power supply can tell you if you can also use a different type of transistor. Also even that designer might have to do some checks before (s)he can guarantee that it will work.

In a properly designed circuit usually the exact model of transistor doesn't matter too much as long as they're at least similar. So similar maximum voltages and current, similar beta etc. Those e13007-2 and 13009 do look "somewhat similar" in my opinion so probably you can use the 13009 and that might just work. But no guarantees!!!

Indeed improving the cooling is a good idea after the failure on a hot day.