definitly sounds like a well planned hit more than random crackheads. maybe not necessarily one of your friends or aquantences but at the least someone in the area or maybe just was visiting the area and seen/heard your trucks. Start lookin around and askin questions, check any local pawnshops or fleamarkets in your area, we found a transit that got stolen from my dads van at a fleamarket about 4 weeks after it was stolen, luckily he still had reciepts and serial numbers for it.
and get an alarm as you are probably already thinking, its cheap insurance in the long run.