Don't ask Peterbilt guys about Peterbilts. Many of them will lie to you and say there is no better feelin than Petermobilin. A Peterbilt is a good truck (359s &379s) but they do have annoying faults.
If you can find an 07 with a Cat, engine serial number starts with NXS, would be a good buy, just avoid any Cummins (EGR problems) or any CAT that starts with SDP.