I agree with everyone here, that working with a medical professional is the best road to take when dealing with a prescription that affects your mental well-being so profoundly. I am on an anti-depressant (Effexor), and discussed MANY options with my doctor before choosing this one. Weight was a huge issue we discussed when picking which option would be best for me, as I clearly stated that I didn't want to gain weight. We had a LOT of issues to contend with, as I also have epilepsy, otherwise my doctor said Wellbutrin would be a great choice.
I've been on my medication for over a year now with great success, but I worked very closely with my doctor to choose which one would be right for me. Having a good relationship with your doctor and expressing what you want to get out of your medication is critical. Good luck to you!