Janelle, this would be worth reading http://leatherworker.net/forum/topic/25239-the-type-of-sewing-machine-you-need-to-sew-leather/
The main consideration in choosing a machine is what type of material you want to sew. A machine that can do thick leather won’t be the best machine for thin leather and fabric.
A cylinder machine is very useful in bag making. If you can only have one machine a cylinder with an optional flat bed is a must. Also a servo motor and a speed reducer would be helpful.