30 is enough Cultists
lol
Plague Marines are auto win, most people have a few squads of 7, usually with 2 Plasma Guns.
The chosen are over costed and not much better than regular
CSM. You could use them individually as squad champions if they're the Dark vengeance ones.
The rest is ok, I wouldn't go for the warp talons, as cool as they look, they're just not cost effective and have no grenades :( A possible 9 Obliterators is a bit much
imo but hey, it's always good to have spares! I'd probably get some Autocannon Havocs (the horus heresy forge world ones look badass
btw)
People may hate you for the Heldrakes, but that doesn't matter!
Just my input

Hope it helps!