I have been wanting to lower my suspension on my 2010 mazda 3i but im not sure whats best to buy.

1. if I buy coilovers(which are very expensive) would i need to buy anything else? or do they have everything i need for good handling, good appearance, ect?

2. I have been looking at the H&R sport lowering springs. if i get these instead, would i need to buy shocks and a strut bar too?

which one would you recommend better?

thanks for your help.