18x8"s on a 200q20v?

[auditude at cox.net]

Hi,

I checked the archives and saw just a few posts about running 18" wheels on a 200q20v.  Mostly questions but not any final answers posted.

I found a set of 18x8 Oettinger RE's with 235/40 Michelin Pilot Sport's on them for a decent price.  However, I am not sure I want to run 18"s.  

My concerns are all that one could have:
added weight over 17"s (my first choice), 
added cost of replacement tires over 17"s, 
speedometer inaccuracy with the current tire size, possiblity of wheel damage with a smaller replacement size (we have good roads here in AZ tho'), 
and of course, whether they will actually fit the car.

I understand the wheels themselves weigh about 26lbs each (I would prefer 20-22lbs).  However, once I get wheels I'll be able to shed the G60's and put on some big reds.  I don't know if the net weight would be lower (and I know it's only unsprung and not rotating).

If I got something way lighter like some kind of BBS or SSR or something it would obviate many of those concerns, but those would be way more $$ which is a factor.  Even so, I would still probably pursue 17"s if it wasn't for this particular set that is available.

I guess I'm mostly concerned about the tires being more expensive than 17" tires, and that they will physically bolt onto the car without interfering with anything.

Any thoughts?

Thanks,

Ken