Well, you can do springs and shocks... But you will be bored with the tuning capablities sooner rather than later. The primary advantage to using coilovers is that ability to control the pre-load on the spring. This will help with right height and suspension jounce. Also the the spring and shock are matched, so the softness you will get from the standard spring/shock set up will be eliminated. Yet another reason is that most shocks are mono-piston equiped, so ride quility suffers when you adjust the valving. Tein is one of the FEW companys that produces Bi-tube designs for RIDE QUAITY and PERFORMANCE. JIC also has this availibe, but they primarily stick to the mono-piston design.
The only problems is they cost more... Bah! Who needs those stupid Altezza lights anywho, save your beans and and get something good.
Just my $.02.