Potty Training... please just work... please please please

So we are in the middle of potty training (so clearly i will mention poop and pee in this post). I need to start this post by saying I have dreaded this day since I found out we were having a baby, potty training doesn't have reputation for fun. We have toyed with the idea of potty training for awhile. I promised myself when we got done traveling this past fall we would try it, major fail. I promised myself before Zach was born we would do it, and then while everyone was here at christmas, and then finally when we moved. When we got to Austin we had to do it. We had done potty chart after potty chart, he earned prizes, we made a big deal out of buying underpants with thomas the train and he knew how to pee in the toliet he just... didn't want to, so we continued with diapers. But as we were getting ready to move I informed him that he was a big kid, and only one person in our family could wear diapers, since Zach can't walk it's his turn. Michael reluctantly agreed, and when we got here he even asked to go in the potty. So last weekend we put underwear on him and started down this fun fun journey. And it has gone ok. He has known for awhile this was coming so he was prepared and we have the peeing in the potty down pretty well. Luckily we also live close to things now so we can run to the grocery store and be back in 15 minutes so using public restrooms is less of a thing... though he has seen quite a few of them. But here's the kicker, for nap time, or fake nap time as I should more accurately refer to it, we wear a diaper, that's ending Monday. And for bedtime we also wear a diaper. I know when he is awake he can go in the potty, but as he pees so much as night (no really he does) I know he can't make it to the potty, and even if he did he won't make it enough not to wake up with a pee soaked bed. Anyway he saves pooping (bet you wanted to know that) for these times. No poop in the potty, just the diaper. Clearly something must be done, so on Monday during fake naps we are taking the diaper away, he isn't sleeping anyway and maybe that will give him the incentive he needs to put the poops where they should go. I have tried candy, shows, toys, nothing provides the incentive he needs to poop in the potty... I'm hoping poopy underwear does what everything else has failed to do. Ok really I am hoping the threat of poopy underwear does the trick because i really really do not want to clean up that mess.  So I need some tips, how did you get your kids to poop in the potty? and it gets better, right?