My suggestion
Duke
4 TB - x4 Blaster, Venom x2 SC
4 TB - x4 Blaster, Venom x2 SC
4 TB - x2 Cannon, x2 Carbine, Venom x2 SC w/Nightshield (Duke's Ride)
8 WYC - Hek w/Agoniser, DL Raider
8 WYC - Hek w/Agoniser, DL Raider
8 WYC - Hek w/Venomblade, DL Raider w/Torment GL & Chain-snares
RAV - x 3 DL, FF
RAV - x 3 DL, FF
RAV - x 3 DL, FF
TOTAL - 1499
HQ 10%
ELT 33%
TRP 34%
HVY 23%
IMO this list takes full advantage of the Duke's special abilities. TB unit has a decent #of shots at range with a 3+ wound, 3 units of Combat Drug using Wyches, and the ability to DS one or more of the TB w/ Blaster Venoms or Ravagers.
I know the consensus here seems to favor Agonisers so I armed a few of the Heks with them to give you the option to engage heavy armored troopers more confidently. I like the Venomblade and wounding on 2s so in the last Wyche unit (and it was a points constraint as well) the Hek has a Venomblade.
As far as vehicle upgrades, I kept the Flickerfields on the targets of priority like the Ravagers. I didn't feel the FF were needed on the Wyche Raiders as your opponent should have his/her hands full with the Venoms and Ravagers, not to mention you probably should be moving at speed to use the better cover save (as well as it saved points to spend elsewhere). You can float the 10points of the TGL and CS from the one Raider around, but personaly I like having a -1 LD around in support of CC or to pester Psychic tests, etc., not to mention maybe I can break a small unit with a chain-snare flyover (fun factor)
I thought fluff wise the Duke's ride should be more pimped out and to keep him a bit more safe from the average rif raf's small arms fire his Venom has a Nightshield.
This list sports 9 vehicles with a lot of ranged AI and AT with the option to get your hands dirty in CC. One option I'm liking the more I think about it is to replace a few or all of the Raider's DLs with DCs.