Just a quick update...
I installed 4 Dorman 974-001 TPMS sensors ordered from RockAuto. I was having major issues with them... at first, only two synced up. Then, one of the two would drop in/out of signal... so I really only had 1 good sensor. I worked directly with Dorman tech support and did some troubleshooting; they decided to send me 4 new sensors directly from their factory. I put the 4 new sensors in tonight and they all synced up, no issues.
I also used a TPMS tool to read all of the sensors. The original sensors I ordered from Rockauto were crap, for whatever reason. Two weren't giving off any reading at all and the other two would take a long time to register. The 4 sent to me from Dorman registered within 2 seconds.
Just another note, my other wheels/tires had Orange Electric sensors in them and they worked flawlessly. They came with my wheel/tire package though, not from a parts distributor.