I have owned a certificated (albeit vintage) aircraft for nearly 20 years (a Navion, imagine a bigger, louder, more fuel consuming Tiger). I've dabbled with the idea of a homebuilt, either something simple and fun like a Fly Baby, or perhaps (since I also live on a airpark on a lake) something like a Sea Rey.
If you want to FLY, I'd recommend getting something already built (either a certificated ship or an already built homebuilt). This will give you something to do (and keep your skills up) while you dabble with the idea of what you are going to build yourself. Even the simplest homebuilts are going to take several years unless you are tremendously dedicated to hacking away at the thing in every spare moment. It is suspected that a lot of the infant mortality of homebuilts come from pilots not keeping their flying skills up right prior to their test phases.