The OEM coils are far superior to any "performance" COPS I've seen. The best bang for the buck comes from Ebay. Uneek and Global have good COPS for less than $100. for a set of 8. They are also warranted and have been a good supplier to the folks on this site.
I'd suggest going back to the stock tune and see if that cures the issue. Sometimes these programmers have a tendency to advance the timing a little too far and you'll end up with the engine running like the truck is running against the wind. You CAN run too much heat in the pistons causing premature failure of pistons. If the engine starts to knock some, expect to find broken pistons. A good place to inspect for too much heat is at the spark plugs. Pull a couple on each side and if they look good, no problems. If they look blue or the electrode is burnt, you're in trouble.