Depth Chart Comparison Script

Need a PHP script for web site that will allow user via 2 drop down menu's to compare two team rosters offense and defense. This is for an online (american) football League using Madden PC (video game) Site is already established up and running and is completely PHP. I would like to be able to use the format from this page: [login to view URL] but add the addtiional "compare" feature so you could matchup any teams offense against any teams defense. I would also like only the starters to show on the comparison page..i.e. only 1 player from each position. Hopefully my details make sense. If interested message me for more descriptive details. Thanks.