I live in Indianapolis, but being such a newbie I really don't know what is available, there isn't a layout in my home yet
Avon Yards would be nice, but I think you would need a tour by a CSX employee due to the increased security woes of our nation. I'll contact a friend of mine whom recently retired from the Avon Yards after 40 years of employment for information.
There are a couple of train groups in town, but on my visits they were deep into reworking the layouts and not running.
Check out the following website there may be a couple of contacts you could make through them:
http://cid.railfan.net/ I believe this would be your best source of information.
There are several hobby shops in the area. I would assume you're staying near the airport, and if that is true "Big Four Hobbies" is in Plainfield. They have a nice selection of RR Modeling supplies, locomotives and such.
The Children’s Museum has a Climax (I believe it's a Climax) on display in side. They had at one time a large HO layout, which has been replaced by a G-scale running the ceiling.
If ya can't find too much I could drive by your hotel after 4 PM and drive ya around the town a little and possibly pick up your dinner
Tomo