Well,
I can't speak to the differences between the Talon and the Scorpio, but I have the TW-400 from Internatrix. The components look EXACTLY the same. The only differences are that the Talon comes with a second control unit, has optional remote start and costs $100.00 more.
Here is the Internatrix website:
Here are a few links about the Internatirx from the board:
Hope some of this helps...