please recommend replacement transistors

I have a broken C3519 and A1386 pair from Sanken, which are in an Onix A-120 amplifier. (I like the amplifier, though I think the 2dB boost below 200hz is an undesirable "feature")

I am looking for replacements.
Apparently the 2SA1294/2SC3263 and Toshiba 2SA1302/2SC3281 are suitable pairs to replace them, but I would like to know what options I have for "upgrades" to the transistors. I am willing to purchase two pairs, and anything less than $10 per transistor is worth considering to me. I also don't different physical shapes, as I can use thermal adhesive to attach them to the sink.

Would you need to know more about the circuit design to pick a suitable replacement? The amplifier is rated for 120watts into 8ohms and something like 150-180watts into 4ohms.
Can I increase the amps tolerance for lower loads, reduce distortion, or make other improvements with different transistors?
 
miekedmr said:
I am looking for replacements.
Apparently the 2SA1294/2SC3263 and Toshiba 2SA1302/2SC3281 are suitable pairs to replace them, but I would like to know what options I have for "upgrades" to the transistors.
Nothing wrong with those. Swapping output transistors is one area where you are likely to realize the smallest benefit, as long as your choices make sense. I'd put in the A1302/C3281 pair and be done with it.