MazdaKev

Hi I'm new to the forum and wondered if I can get some advice. I have a 2006 mazda mx5 1.8. I have purchased a set of Eibach 45mm lowering springs, my question is......is this too low? I have the standard 16" alloys, will they rub anywhere? Also I intend to have the wheel alignment done but if I I then fit 17" wheels would this affect the wheel alignment again? I would very much like to keep the 45mm lowering springs but if it turns out it's inadvisable to fit them I am able to change them. Lastly, what sort of cost should I expect to pay for wheel alignment designed for road use. Many thanks.