I've had problems with acne and oily skin my entire life, spent endless hours researching, and tried every product you can imagine (including accutane which messed with my head and I stopped after 1 week when my hair started falling out!!! It did stop the oil though, just not for me). Finally I found something that worked and thought I'd share this combo.
Although I can't tell you the perfect mix, I'll tell you my experience. I read all the threads that said take a massive 10g of B5/day, so I took 20g (b/c I'm a large human (- for the first five days. During that time I did have a breakout that surfaced, but no more after week 1. After 5 days of mega dosing, I read that taking L-Carnitine concurrently may enhance the effect and also allow you to reduce the B5 dose.
Completely experimenting with my own dosage, I lowered to 10g B5 and 250mg of L-Carnitine/day. Within 3 days my oily skin was probably 90% reduced, with dry lips as the only side effect. This is not to recommend my ratio as the "perfect ratio" for the cure, rather to share my experience. I'm constantly changing the ratio myself to see what works best, but wanted to share this with others, so they won't have to go the long route like I did. Let me know if you have any questions, and good luck!