Yaris 2003 P2 T-Sport Upgrade Questions

[jrampton]

I've had a look around and can't find the answers i am looking for.

Suspension - I want to lower the Yaris at some point, should i just go with lowering springs or go with a kit that has shocks and springs ? Are the stock Toyota Part up to the job ? Will a suspension kit be too stiff and make it really uncomfortable ?

Induction - Looking at induction kits they seem to be £150+ are they worth it ? Should i go for a Panel filter instead ? thoughts ?

Exhaust - I've seen some reviews that say some exhausts are not that great for the Yaris, i don't want a massive can on the back just a mild sport exhaust ideally, i want it to sound a little better but not go deaf !

Speakers etc - I upgraded the Speakers in my old Yaris that was a 5 door, this one is a 3 door has anyone mounted Speakers in the side panels ? Does it work ? Will they just vibrate ? Looking at 6.5" components for the front doors.

Any other handling upgrade recommendations ?