As a lifelong (28 years) KC resident, I would be glad to assist with any KC area questions.
First, just FYI.... Garozzos is currently closed. There was a fire above their restaurant about a week ago - and there was extensive damage to the building. Actually - it's the original location - I think they have another location in Overland Park - but not positive on that.
Today is the first day in the last week that the temperature has dropped below 100 (it was only 96 today). So.... be prepared for a HOT game at Arrowhead.
If you want BBQ definately go to Gates or Arthur Bryants. Whenever important folks (Presidents, Vice-Presidents, Celebrities) come to town - they usually go to one of those two BBQ restaurants.
There is a Marshalls on I-70 in Independence. If you are coming from Indiana, I would assume that you will come I-70 - so look for the "Noland Road" exit. You will see the strip center with the Marshalls from the highway - so it will be easy to get there.
As far as "cheap" Chiefs apparel. Most local Wal-Marts have Chiefs/Royals apparel. You will probably find it there priced lower than most other places. Near the stadium (on 40 Highway and the Blue Ridge Cutoff) there used to be a little gas station that would sell a bunch of merchandise on game day. It was the "cheap" stuff ($10 shirts - $20 sweatshirts), and the quality was usually lower. They are probably still there if you want some game-day items to wear. Other than that - go to Wal-Mart. Since the Royals are doing so good, and the Chiefs are looking promising... you probably won't find too many sales on the merchandise.
If you have any questions about KC, feel free to ask. Like I said... I'm a lifelong resident, and I work for the KC Police Department - so I should be able to help you out.