Hi, you may not find 1/196 but 1/200 should be close enough.
Also you won't find them ready-made to populate your decks and rigging. You may have to resort to some cut and re-glue to have them in the poses yo want.
You can find them on e-bay from many manufacturers (unfortunaly many are knock-offs), one main manufactuer is Preiser from Germany. Their line is also carried by many railroad suppliers. Some of the trackmen can be used to man the guns with a little trimming. Other standiing figures can be out on the afterdeck. These at that scale you may only have to paint to match the clothing of the period.
Preiser makes their figures from styrene, regular kit plastic so you can modify, cut reposition and glue, quite easily. Then use milliput or other standard puttys to make alterations or hats. The knock-offs use a different plastic so you may have to use an ABS type of glue. Most hobbyshops carry this in small bottles.
Hope this helps.
Peter.
On the bench;
Converting a 74 gun Heller kit into HMS Sutherland; 1/200
Converting Bomb Ketch into HMS Harvey; 1/200
Cleaning up an Aifix lot of 54mm figures, for converting.