Selecting options for an STi kit.

Probably been asked before, but I've tried a search and I'm not getting much good info. Maybe I don't know what to search for...
Anyways, I'm pretty sure I know what options I'm going with, except for a few which I'm unsure about:

Speedster Tail Kit. I'm wondering about the pros and cons of this option on an STi. Less drag I'd presume... But bad for a STOL plane?

Also the Chomoly Streamline Wing Struts. Are they worth $3500 in your opinions?

Just interested in hearing your thoughts.

Thanks,
Caleb