Btw the wiki does not say how many longboats the westerlands have just larger ships so... number?
at the battle of Blackwater Bay, the Lannisters fielded 47 War Galleys. Stannis had a fleet of 200, but 70 were mercenary ships from Myr and Lys, and 70 were commandeered sailing vessels like cogs and carracks, which are generally fairly useless in a battle, so he had about 60 Galleys. Given rebuilding and the likelihood that the navy would be bolstered to deal with the Ironborn threat, the Crakehall navy likely sits somewhere in the 50-80 Galleys region.
As for the North, they have had no presence at sea since their fleet was torched by Brandon the Burner hundreds of years before the events of ASOIAF. SO for the Starks to build a navy, it would probably sit at around 30-40 galleys, since the North has had no use of shipwrights for hundreds of years and they would, as a result, be hard to come by. The trade of a shipwright is a dying one in the North, it would seem.