Modafinil and Buproprion

Using both Modafinil and Buproprion? Diagnosed a little more than a year ago, at 39. Concerta and Adderall both posed dysthymic side effects, even when the latter was paired with Wellbutrin. The Wellbutrin definitely helped impulsiveness too. In Canada, we're still awaiting the newer stimulant formulations. We do have access to Provigil (Alertec), however. I have the psychiatrist's blessing to start a trial while we wait for other stimulant choices, but what I want to know is whether I can keep the Wellbutrin (maybe lowered to 150mg/d from 300mg/d). Anybody familiar with taking both of these drugs for combination ADHD without any comorbid conditions or disorders? I understand that they may interact in a manner so as to increase each others potency, but if I'm starting on the lower 100mcg/d dose of Modafinil and the lower dose of Buproprion, I don't see that as much of a problem. I should mention that my curiosity is led by the fact that the psychiatrist doesn't write the prescriptions. He just sends a letter to my GP and we discuss where to go from there. The green light came last week and the drugs start next week, after a baseline liver number has been established (and I've dropped the Wellbutrin, either to 150/d or zero). Thanks in advance.