I used to have an Avenger 50. Great amp, wish I hadn't sold it. It's not super high gain, which is why I parted ways with it, but in hindsight, I think if I had boosted it, I would have got where I wanted to go.
That said, it didn't have channel switching capabilities, just a high and low input. That didn't work for me.
If you can get a SLO, I would, as the Avenger is based off that circuit and the SLO is pretty much bigger and better in every way.