T.H.
I just wanted to say that you can make any pill into the pill that only gives you a period 4 times a year! I'm on the Mirena now but before, before Seasonale even came out, I started skipping the placebo week and going on with my pack and just totally skipping my period. It totally worked for me. I talked to my doctor and my pharmacist about it and both agreed that it was just fine. Personally I didn't really ever have breakthrough bleeding although it is possible. But, if you're taking the pill correctly then even break through bleeding isn't a regular period b/c you're not ovulating so you're still safe.
So if you go the pill route, my suggestion is to just get the one the works the best for you and gives you the best copay option and skip the placebo!