Sup all, i am preparing to purchase a warhound titan from forge world and i was wondering what the best weapon combo would be? i dont have the book yet, but army builder give a bit of the stats.....however some of the weapons have special rules and im a bit confused on some of them.

this is what army builder says:
vulcan mega-bolter: R12"-36" S6 AP4 Heavy 10, barrage rending

plasma blast gun: R12"-54" S8 AP2 Ordinance 1 blast titan killer (Additional rules)

inferno gun: R12"-46" S7 AP3 Heavy 3 blast no cover saves (Additional rules)

Double-barrelled turbo laser: R12"-72" S9 AP2 Heavy 2 blast

i would like to know what those additional rulz are,and how the vulcan gun can be barrage and what is the best weapon combo...i was thinkin plasma blast and vulcan bolter, thanxs