Lord - anything with Str 8 AP3 or better and he's dead, it's why people take princes, or you can take sorc's as you can hide them in units and thier powers tend to be much more useful than a lord.Lord of khorne daemon weapon, jugger or on foot, meltabombs
1-2 Dreads with close combat weapons and extra armor
8 or so Chosen with plas/melta
8 berzerkers champ power weapon
2x 8 CSM's w/2 plas/meltas
2x rhinos extra armor & havoc launchers
1-2 havoc units or 1 havoc unit and 1 obliterator unit of 3
Dreads - with a 1 in 3 chance of going nuts they tend to be a liability, the best way to go is usually 2xCC which means they only have a 1 in 6 chance of just standing and shooting but on the flipside you might not want them to move yet and they go charging towards a bunch of melta and get torn open.
Chosen - i run 5 man squad with 5 meltas in a rhino and usually outflank to go tank popping you can use plasmas too but you risk killing youself and at 32? pts a pop i don't like taking those risks.
zerks - you only have 2 rhino's in your list, i pray you put the zerks in 1 because foot slogging troops will get ripped apart, also while it wastes the I5 charge zerks have, giving the champ a fist for 4 str9 attacks on the charge is likely a better choice. Reason for this is the amount of mech these days you need every bit of antitank you can get and you really don't want to find yourself in CC with a dread or some nasty MC where you're going to struggle to hurt it.
CSM - you can only take 1 special weapon unless you take 10 marines so it would be better to make 1 squad and stick them in the other rhino
Havoks - ...i've considered using them but oblits tend to be just too good and the fact oblits can move and shoot, have access to several weapons including powerfists in CC i find it hard to justify using oblits, however you can use them similer to chosen with 4 meltas in a rhino.
Oblits - Rock 'n' Roll
The biggest issue i see is the lack of mobility, on a 6x4 board foot slogging is just too slow.
I can slap together a simple competitiveish list if you like