A better place to ask is probably the programmer forum https://stackoverflow.com/questions/tagged/osx
But offhand I think you can make a few different variants of your .app
each one registering their own Services action. Those variants could then launch your "main" app to do the heavy lifting.
These variants could be bundled inside the main application, like I see some examples here:
/Applications/Adium.app/Contents/Frameworks/Sparkle.framework/Versions/A/Resources/finish_installation.app
/Applications/Android File Transfer.app/Contents/Frameworks/Breakpad.framework/Versions/A/Resources/crash_report_sender.app
/Applications/Android File Transfer.app/Contents/Resources/Android File Transfer Agent.app
/Applications/Android File Transfer.app/Contents/Resources/Android File Transfer Agent.app/Contents/Frameworks/Breakpad.framework/Versions/A/Resources/crash_report_sender.app
/Applications/Google Chrome Canary.app/Contents/Versions/26.0.1400.0/Google Chrome Framework.framework/Resources/app_mode_loader.app
/Applications/Google Chrome Canary.app/Contents/Versions/26.0.1400.0/Google Chrome Framework.framework/Resources/crash_report_sender.app
/Applications/Google Chrome Canary.app/Contents/Versions/26.0.1400.0/Google Chrome Helper EH.app
/Applications/Google Chrome Canary.app/Contents/Versions/26.0.1400.0/Google Chrome Helper NP.app
/Applications/Google Chrome Canary.app/Contents/Versions/26.0.1400.0/Google Chrome Helper.app
/Applications/Quicksilver.app/Contents/Resources/QSDroplet.app
/Applications/Stainless.app/Contents/Helpers/StainlessClient.app
/Applications/Firefox.app/Contents/MacOS/crashreporter.app
/Applications/Firefox.app/Contents/MacOS/plugin-container.app
/Applications/Firefox.app/Contents/MacOS/updater.app
/Applications/TextMate.app/Contents/SharedSupport/Bundles/ActionScript.tmbundle/Support/bin/XTrace.app
/Applications/TextMate.app/Contents/SharedSupport/Support/bin/CocoaDialog.app
/Applications/TextMate.app/Contents/SharedSupport/Support/bin/CommitWindow.app
/Applications/Xcode.app/Contents/Applications/Accessibility Inspector.app
/Applications/Xcode.app/Contents/Applications/Application Loader.app
/Applications/Xcode.app/Contents/Applications/FileMerge.app
/Applications/Xcode.app/Contents/Applications/Instruments.app
/Applications/Xcode.app/Contents/Applications/OpenGL ES Performance Detective.app
…