I would start out by checking the side of your tire to confirm what size you are currently runny. The stock tire size for the commander is 265/65R17. So if you are already running a larger tire size, and don't have a lift, then you will really need to put a lift on to go with anything bigger.
The stock tire size is 245
/65R17 (unless it came with an 18" wheel from the factory).
2006 Steel Blue 5.7L HEMI Limited 4x4 Build Date: June 9, 2006 Hour 14
Interior: Dark Slate/Light Graystone with Saddle Brown Leather Seats
Quadra-Drive II, NAV, DVD, Trailer Tow Group IV, Off-Road Group II, Remote Start, UConnect, Rear Backup Camera, Chrome Wheels,
Magnaflow cat-back exhaust, Daytime Running Lights enabled, 2" Rough Country Lift with 265/70R17 Goodyear Wrangler AT/S