I've also been shopping for a Signature. I think you are wise getting it inspected as there are so many systems and some can be costly to repair.
There are several RV dealerships in the area. I would start by contacting each repair center and ask about inspections. Best of luck with your new Signature.
Premier Coach Services
www.premiercoachservices.com/
3423 NW Tullison Rd, Riverside
(816) 587-1500
Lifestyle RVs
1100 NW Pamela Blvd.
Grain Valley, MO 64029
Phone: (816) 847-1699
Trailside RV
888) 860-7802
http://www.trailsiderv.net/