Foundry produces some 18th century civilians, so they could be a match up for your pirates. But as I heavily dislike those Baker apes, I cannot recommend them. Maybe you could convert some Victorian figs, mainly the ladies.
Eureka do some civilians either, but they seem a bit late (more Rokoko style).
If you're not too serious with historical accuracy, there's a broad choice of military miniatures. You could use Perry's AWI range (lovely stuff) or the rather tall Redoubt minis for the FIW. Compared to Foundry pirates the latter would match up me thinks.
For more 'in period'-gameplay use Marlburians, e.g. the ones from Foundry. They are a bit small, but you won't mix them with your pirate scum? :wink:
Personally, I don't like the somewhat chunky Front Rank miniatures, but their Marlburian ranges are quite large with some impressive figs in there.
The said manufacturers also carry a lot you could use as militamen. Besides this, Conquest Miniatures produce very nice farmers and colonial soldiers in informal/campaign dress. They are worth a closer look.
Hope that helps a bit.
