3x Land Raiders (750pts)
3x Terminator Squads (750pts - 1,500)
Belial + a couple of upgrades = 1,850
I would go for a Crusader, and two Godhammers.
This presents him with a wall of AV14. Better yet, only his Vendettas, Banewolf and Manticores can harm it over 12".
The max range of a Lascannon is just 48" IIRC, however, so you'll need to deploy in cover, drive at top speed and pop smoke, and then fire at his Vendettas, his Banewolf and his Manticores in that order (IMO).
Once they're knocked out - and you can consider adding in some Cyclones or A/Cannons to help knock his tanks out - your Terminators can squish his Veterans and then hop back into the bunker-tanks that nothing he has can touch.
I think that'll work.