GHQ makes every class for the Java Sea campaign in 1/2400 I believe. Ah, wait, GHQ doesn't make Langley or Sea Witch.
CNC makes most of them too but only one Dutch class: De Ruyter
Panzerschiffe makes all of them.
Viking Forge makes some of them.
The Java campaign is well supported in 1/2400. GHQ makes aircraft for this scale. Beautiful but tiny.
Modern 1/2400 is well supported, in spots, too.
GHQ has small American and Russian fleets covering the '80s to early '90s. They also have a smaller British contingent covering the Falklands engagement.
CNC has American and Russian fleet units from the '70s to late '80s.
Viking Forge (mostly SeaBattles models) covers the American fleet from the '50s to the late '80s (a few later, especially amphibians). VF includes auxiliaries. VF also covers the German navy from the late '70s to the early '90s and also the Japanese fleet (also SeaBattles models. Very nice)
Superior (Alnavco) has Russian and American fleets covering the '70s to the late '80s. A few Italian and French over the same period and some British ships covering the Falklands.
Alnavco also imports some SeaBattles models that VF doesn't carry. Mostly American auxiliaries.
Sea Wulf (LKM) supports, in 1/2400, the British for the Falklands and intends to add the Argentines.
GHQ also provides aircraft for moderns in 1/2400. Not a wide or comprehensive range but some.
Bang for the buck. Panzerschiffes are cheap. When well painted and vertical detail added (masts) they are pretty much indistinguishable from GHQ at a distance of several feet.
VF are reasonable. I think CNC are very nice (but their WW2 ships, and some of the moderns, don't have masts).
Because of the exchange rate Sea Wulfs tend to be almost as expensive as GHQ but of lessor quality. But where else can you get Leanders (of many flavours and Counties?)