foxie - Alligator and croc is durable, but if you are in very high humidity or get it wet the scales can blister. This is the biggest drawback for me. I have a gorg Ferragamo alligator bag, that does not get used as much as it should. I'm assuming you are a male and would be pulling a bifold out of your pocket or messenger bag, and maybe getting some rain exposure. But if you do not have to worry about rain or constant high humidity - go for croc/alligator. They are so beautiful.
As for finishing, I can give you a little info, but a BV SA can probably get some more info. The best croc finishes are made by rubbing with agate to polish into a high shine. You may have heard this before...that they are finished with a stone. Scales are made of keratin and like your fingernails, buffing will shine them up. Then there is glazing. Glazing is a coating to protect and keep your croc shiny. Some manufacturers skip the agate polishing (bad/cheepo) and glaze only. Matte croc is finished gently or sometimes sanded to uniformity.
Fume (fumed/smoked), Lave (washed), Tie-dye (self explanatory) are just treatments to alter the look from a natural scale appearance.
Fumed skins are exposed to fumes, which gives the scales a darker appearance around the edges of the scales. I doubt it is actually smoked with wood smoke, but I do not know what chemical is used to fume croc. Or it could even be dyed to look like something that was fumed.
Lave - I have no idea how this is done.
Ostrich is very durable, too. I have an Ostrich Kelly that has been rained on and it never spotted or changed.