Pammy, Here are three leather shops I've found reviews on. It will give you and Andi a start!!
Silvia Eisele Cueros Arenales and Austria Phone: 541148299358
www.silviaeiselecueros.com.ar El Boyero on Florida Street. The best quality stuff with different kinds of leather. Not bargain prices, but it's top quality.
Silvia y Mario, a great family owned store. Great prices and designs. Leather jackets, shirts, skirts. High quality garments Address: Marcelo T. de Alvear 550
http://www.silviaymario.com/en/