The Musketeers are cast in three sections legs, body (inc arms) and head. So you can change the position of the figures and even switch the parts round if you want.
They are true 25mm so look small compared to some of the newer 28mm to 30mm GW and Confrontation minatures.
Wargames Foundary also has a number of suitable ranges these are the more common 28mm sort of scale most minatures are nowdays.
Reaper has a boxed set of pirates. They also have a couple of assorted miniatures that might fit into the swashbuckling genre. Not a large amount of miniatures but some.
Foundry probably has the largest selection. There is also the miniatures for the 7th Sea Game by AEG. I'll see if I can locate who makes those.
[Edit]
I guess that the 7th Sea miniatures are from AEG, but they seem to have been discontinued. I did find most of them for sale on e-Bay. Just do a search for "7th Sea" and you will find them.