Give us a little more description on "skips and bucks". Under what conditions does this happen? For example, if your engine hesitates like it is falling on its face under heavy acceleration the problem could be a misfire. Without diagnostic trouble codes to tell us whether it is a random misfire or a cylinder specific misfire, we can only give you generic responses such as change plugs, wires and check fuel pressure. Take the car to Autozone and have them scan for diagnostic trouble codes. They do that as a free service. Let us know what you find.
The vehicle has 108,000 miles but how long have you owned it. Do you know the entire maintenance history. If it has been a while since plugs and wires were replaced, or if you don't know when they were last replaced, that is where I would start. Most of the misfires I have seen came from a cracked ceramic insulator on a spark plug, or a split or cut in a spark plug wire.
More information will help us to help you better.
2001 Bonneville SSEi (retired at 365,000 Kms.)
2014 Jeep Grand Cherokee Overland (yes, I know its not a GM)