What to pick up next?Looking for suggestions.

Hi everyone Ill get straight to the point. I am planning on making some IG purchase in October and I am looking for recommendations.
Current models I have so far-
1)Ciaphas Cain(Unpainted)
2)Cadian Command squad(unpainted)
3)30 x Cadian Shock troopers(Fully painted)
4)10 x tempestus Aquilons from Kill team
5)5x tempestus Scion (painted)
6)5 x ratlings(painted)
7)10x Kasarkins(unpainted but primed)
8) 1 x Lemun Russ (Painted with changeable turrets)
9) 1 x Rogal Dorn(Base paint applied detail work left w/ changeable turrets) + its my current painting project.
10) 1 x Scout/Armored sentinal(Painted)
11) 1x Centaur RSV(Primed/unpainted)
12) 2 x Griffons (painted)

I dont plan on attending tournaments at least this year but simply to just play casually. I feel like at a good mix of infantry and vehicles if I aim for a 1k point list. So I am leaning towards artillary, Machine gun squads, FoB or Bulgryns since I can use Ciaphas Cain as a commisar instead in official plays according to my LGS.