Something to take note of (mainly your budget). Most people, after doing the Alpine upgrade, upgrade the underseat woofers to L7 ones, as the Alpine Kit doesn't replace the underseats and there isn't enough low end.
Edit: Try your best to hear one set up first.
2008 E92 335D SE
2010 E90 320D SE
1994 E36 318I SE
1996 E36 316I SE