3 days really isnt enough time to get on down to the Springfield/Branson area from Peoria. I'm not really familiar with the STL area to be able to say for sure the best area to stay/see, as I usually go into Arkansas to ride around. I did tour the Anheuser-Busch grounds though. Pretty cool. SW Missouri, Branson is cool, especially the old section away from the "strip". Lambert's is a must, 14 miles south of Springfield in Ozark. Bass Pro in Springfield is great as well.