I think most big seat makers should be able to offer you new rails and hardware that will make seats fit into your car. The hardware should come with any seats that claim to fit.
And for springs, I'd go with Eibach. The Pro Kit is a great buy for the sportier ride, and the 1.5 to 2 inch drop. Eibachs Sport Line kit is a lower drop and probably costs around the same...
You'll need some camber adjustments after the drop though most likely. You can get kits that just bolt into your existing suspension. It's cool,
Welcome to HAN by the way. Are you American?