GoldMine21, where I go to prospect in Pennsylvania sounds similar to your area of Missouri. Those PA locations were barely touched by the glaciers that brought gold south from Canada, so the gold is very minimal and very small. I do know there's some there however because I was going to properties where our club has permission to join (suggestion: go to places where others have found gold. Sounds like northern Missouri would be better.)
After dozens and dozens of days in those PA streams, using a classifier and pans sometimes and a stream sluice other times, my results are something like this:
1. about half the time I get skunked.
2. the other times I may find one very small piece or a few small pieces
3. once I found a small flake
It's because of #3 that I don't get discouraged when #1 happens. You've got to just keep trying.
You didn't say anything about how much practice you've had with panning. Have you bought pay dirt and practiced in a tub at home? (suggestion: buy paydirt and practice. When you know you can get the gold at home, you'll have the confidence to go out in the field and know you'll get gold if there's gold in the dirt you're digging.)
Finally, it sounds like you know not to get a blue bowl for the field. Good, don't do that. If you're going to spend $75 on something for the field, get a sluice of some sort. It'll increase the amount of material you have to run dramatically, and in areas with very little gold it's all about the amount of material you run. You don't need the famous Bazooka sluice; any sluice from a reputable maker will catch gold if set up correctly. I happen to have a Buckabilly 7" wide sluice.
Good luck and have fun!
- Brian