The classic (and by most opinions, best) crew figures are the Revell ones included with Cutty Sark, Constitution, and Golden Hind. The twenty or so are appropriate for a merchantman, but way under need for a combat ship.
Model railroad suppliers are your friends here.
N-scale is about 1:140 to 1:160
Z scale is 1:220
TT Scale is bang on 1:120, but is harder to find figures for.
T scale is 1:450, and is very hard to find things for (including train bits)
There are photo-etch and 3d printed figures for 1:350, 1:400. 1:600, and even 1:700 (those last three being nearly exclusively photo-etch, and in limited ranges.