Unfortunately you have to pick powers when you pick your army, it say so on the librarian psychic powers page (57 I think) at the top.
I have thought about multimeltas, they give me some extra punch but they dont have the reach or duality of a missile launcher, I think only play testing will decide this point.
I like the idea of hunter killer missiles though. It means the ironclads can be a threat anywhere on the board, I'll have to jiggle some points about but I'm not sure where, dropping the Combi weapon will give me 1 at least.
I have thought about multimeltas, they give me some extra punch but they dont have the reach or duality of a missile launcher, I think only play testing will decide this point.
I like the idea of hunter killer missiles though. It means the ironclads can be a threat anywhere on the board, I'll have to jiggle some points about but I'm not sure where, dropping the Combi weapon will give me 1 at least.