Ok, fist gen IS was a no go.....asking way too much $$$ for the wheels & with the shipping costs was just nuts.
But.....after calling my dealer, they confirmed that a set of 17" from a 2008 IS 250 AWD (from a local member) will fit 'plug & play' without any issues even though they are 8" in width, as opposed to 7.5".
Also found a pretty good tire/wheel calculator tool here...
http://www.wheelsmaster.com/rt_specs.jsp