I have a 78 280Z with 225/50/15 tires and wheels. I will be installing a fiberglass areo kit including side skirts soon. I would like to replace my shocks and springs and eventually bushings. Most springs I see lower the car aprox an inch. Will I have a problem with ground clearance? I don't want to wreck the fiberglass. Can anyone recommend the best set up? I have been looking in the Motorsport catalog. Thanks alot.

 

With any lowered Z, you always have to be careful with the air dam on the front! I had broken my fibreglass one twice before I got fed up and bought urethane. However, I don't think it will be a problem if you watch out for parking curbs and the like.
As for suspension set up, it really depends on how you plan to drive the car. If most of your driving is on the street and you are looking for a little better handling, then the Tokiko spring/strut set up works very well (as do Eibach or many other reputable brands). If you are interested in competition, you will generally need a stiffer set up which translates to a very rough ride on the street.
I hope this helps a little. I welcome others who have tried other set ups to chime in here...