(9x) Chosen - Meltagun - Mark of Slaanesh - 208
Rhino - 35
This unit make jesus cry. seriously. i'll explain why:
you are payng 208 pts for 9 marines with an attack more, with no special abilities nor peculiar capabilities in cc, not only, when they disembark, they are going to shoot with their bolters alone because they do not have a special weapon to fire...so it's a 208 pts unit useful only vs small, squishy backfield units (30 orks will just eat them alive). the lord inside is just an easy prey, with this unit.
I suggest you to use chosen's strenght: special weapons. so, no cc unit but a firing squad, with the cc dissuasion given by the lord.
So, 7 models, 4 meltaguns and mark of nurgle + VotLW = 201
less points, more resilient, more havoc when shooting.
My two cents
Edit: also this
Helbrute - Twin-Linked Heavy Bolter - Combi-Bolter - 110
Is plain worse than a twin linked autocannon for 105 pts. you save 5 points and give meltabombs to the War of Choas champion