welcome to the Alfaowner land.
You've done a great choise by staying with Alfa, and you'll be happy with the SW. The JTD16V is indeed a great engine (but I'm not into the dark side/diesel
About the wheels... it's all a mather of opinions and personal tast if you ask me. Pesronaly I don't like to see the SW with the supersport wheels, not at all. They are ok on the 147, but they give a look to SW that she doesn't naturaly have... they are to much flash
But I do like the 17" alloys that come with the facelifted 156.
If you want to go and make the change, there wont be any problem. The manual book should say what's the right pressure for 215/45/17 tire/wheel combination. But then, it also depends a of your driving.
About the side indicators, go for the white (clear, not cristal) ones.
The Alfaowner shop has them, have a look: Alfaowner shop
In the mean time, you can also have a look at my little website...
(2011) Alfa Romeo Giulietta 1.6JTDm, Pack Sport 17", Pack Comfort
(2009) Alfa Romeo 159 1.9JTDm 16V QV, 170hp+360nm, Bilstein B4+TI springs, ConnectNav G2, Autodelta Air filter, Brembo Disks, Satin Mirror Caps
(2002/2009) Alfa Romeo 147, 1.6TS QV, Autodelta Remap, Autodelta Air filter, Eibach Pro System Kit
Social and Automotive Sports Photography