Looking for some advice, should I buy this Helix amp?

I have been offered a great deal on a Helix DSP M Six ($750). I have a 2019 Kia Sorento, I've got type r comp and coax 6.5s + 1 inch tweeter ( front and rear). I don't have a sub installed but do have 2 12s, going to downsize to one (too hard to move the box).
I have a NVX 1100 (4x80@4 ohm, 1x600@1ohm).

Perhaps I'm wrong but I feel I'm going to need a few things:
  1. Better speakers
  2. Get the DSP tuned
  3. A mono block (that's fine, no big deal)
  4. Deaden the doors (planned already).
The issue I'm concerned with is the better speakers. Also the tuning. I don't know anything about sound theory.

Am I overthinking this or should I stick with what I have for now? If I should proceed, could use some recommendations for speakers if you feel that's needed (probably just front).