What leather should I buy to make a vintage Coach-type bag?

[Auden]

Hi, I'm new to leather. I would like to sew a leather bag that's not extremely stiff/heavy.  
 

What type of leather am I looking for? And about how much should it cost? 
 

I think I would prefer to use a sewing machine (Singer 31-15). I would prefer the bag be unlined, but I'm open to lining. I was thinking at first to use 1-3 oz leather, but I do want the bag to last. I like the "buttery soft" leather texture, but also the flexibility. I'm not sure how to explain it. "Vintage Coach" is the best I've come up with. 
 

I also looked into buying a vintage Coach bag on etsy and it might be less expensive to go that route, but I want to learn to work with leather and customize the dimensions of the bag and pockets. 

Thanks!