Ragetti's costume is rather plain.
Here's some good ref pics.
Pic 1
Pic 2
Pic 3
Pic 4
The breeches, vest and shirt can be easily had from any historical re-enactors supplier like
Jas. Towsend & Sons, or any providers of pirate and/or renfaire garb, lots of stuff on the bay.
Depending on how accurate you want it to be and how much you want to spend, suitable items could probably be found by thrift store shopping, also. That would include some big old buckles--if nothing in the belt section, check large women's purses for a good buckle.
His most difficult item would be his coat, and you could mod an old suit coat, if you bought an old suit so you'd have the material from the pants to make those turned back lapels.
Shylaah