2SA1065/2SD2489 substitutes

I'm working on a Technics audio amp from the late 70's with blown outputs. 
I've found one source (in Europe) for these transistors, but they're
asking 
$20 each for them and I am concerned about counterfeits.

They are 150V 10A 120W, with an f(T) of 50MHz... they are faster than 
anything I can find out there.

1.  Is it im****tant that I replace them with units with comparable 
current-bandwidth product?
2.  Can anyone recommend a substitute?  I was thinking maybe MJ21195/96,
but 
they're only 4MHz.
3.  Can anyone recommend a source for NOS Jap transistors that sells
these?

Thanks
Dave