From what I've seen on TB, the back line 600 amp is a good amp for the price. I say keep the head.
I'm actually surprised your 410's are not boomy for you.
Sounds like your looking for lows and punch.
I suggest looking at the NEO 12's.
If you need more volume and willing to sacrifice weight, the GK NEO 412 hits the spot at 4ohms.
If you need an overall one cab, one trip, packs a punch, the GK NEO 212 would be your ticket.
If you want to play smart, get 2 GK NEO 112 each at 8ohms. Vertically stacked puts one speaker at ear distance. You can also split them up, one for home practice, one for studio practice, and both for gigs if needed.
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