HSU repairing the current one is about $120 including shipping.

A new Dayton SA240 is about $125 after shipping. Cutout dimensions are 8.5x8.5, so it should be a perfect fit in the VTF-2.

$215 for a new HSU amp.

Would the more powerful 240w Dayton improve the quality of the sub over the HSU amp, or is more power just going to make it less likely that something gets damaged at high volumes?