couple of upgrade questions

1. Is the 2.0 motor in my MP5 the same as the one that was in the old Mx-6 turbos? Wondering if the exhaust manifold with the turbo would bolt up. 2. Are the Mazdaspeed cams worth the money? 3. Were can I get an upgraded ECU at? 4. Does anybody know were I can get the silver trim rings for the dash guages? I found an old thread were a guy had made them. I emailed him and have got no response. If I could get the CAD design for them I could have my buddys dad make them for us again. 5. Were does the 2003 and up have the tweeters mounted? Are they in the black triangles behind the mirrors? What size are they? (Dont want to have to cut holes in the doors for my Polks) 6. What size tires will fit on 18's and not rub. (car is lowered 1.3") Im guessing 205/40-18's. What offset of rims should I look for too. Thank you all.