Using a bar limits range of motion, but, like a compound bar movements, allows you to work both arms at the same time.
Seated incline curls, and standing hammer curls, will work the muscle through a full range a motion, which will reduce your chances of injury; developer a longer, and fuller muscle, and maintain proper flexibility. You should work on your rotation, separately, rather than doing 1/2 or 1/4 reps for just biceps. You should include rotation in your forearm routine to preserve the range of motion / supination / pronation of your arms. With very light weights, your can work on your your rotation doing standing hammer curls. Seated incline curls will allow you to work your arm through the complete range of motion with regard to concentric movement of your biceps towards your proximal side / anterior side (that is, taking your wrist towards your shoulder, without rotation, going from full extended to nearly fully contracted). You won't be able to use heavy weights if you have proper form. That's fine.http://quizlet.com/1942274/muscles-of-the-shoulder-and-arm-flash-cards/
You should feel free to research this on your own. I've tried to get you off to a start here.
Note that the flash cards describe the anatomy of your arms and shoulders, and the various muscle actions. You can infer exercise movements from the anatomy charts, with the most important thing being stretch, full range of motion, and proper agonist / antagonist development.
Some folks find the "E-Z" bar more comfortable, but, any bar that impedes your range of motion is not the most productive way to work a part. You'll want to include some movements to work on your rotation, being sure to use caution not to injure yourself.
I use weights as small as 5's and have nearly 20 inch arms at 5'5". It's important you understand sarcoplasmic vs muscular hypertrophy and the proper training method for the objective.
Generally speaking, because of the way the bar (either one) binds motion, you are better off doing dumbbells. Many folks that study this say that EZ bars should be taken out of gyms.