When you buy different packs of clothes, by mastering a few simple skills in Marvelous Designer, you can combine the clothes properly with each other so that the clothes overlap and interact with each other. Such an event is more difficult to do in FBX and Object format, and what you do with ZPRG format in a few minutes may take you a lot of time with FBX format. If you are not familiar with how to do this, you can see the tutorial on this topic in my blog
https://www.artstation.com/saharkhazeni/blog/Ag7lW/how-to-make-a-complete-outfit-from-separate-clothes-in-marvelous-designer-with-english-subtitles
Also, all the clothes of this outfit can be bought in my store. Note that, except for the hat, none of the clothes are designed for pirates, but with a smart combination and the right materials, it can get the closest result. If you need advice to prepare products, leave a comment or send a message. I will answer you as soon as possible.