I've been through two sets of springs, a spring and shock combo and I'm on my second set of coilovers. If I had to do it all over again, I would just go straight to coilovers and save myself the time, energy, and money of course. Coilovers just feel better, the adjust ability is a lot nicer than just having springs and being done with it, and because you will eventually go from springs to coilovers more than likely, it'll be less expensive of course to go straight to coilovers, then keeping them.
That's my opinion