The shortest built times of any homebuilder I know is 12-18 months. Some are measured in decades. Right now, a guy I know is building a Glastar 2+2. He "considered the time to build" & figured he could beat the factory builder-assist program's timetable. Well, he's reassessing that conclusion now-- been working on it for maybe 6-8 months now, literally full time (8 hours a day,5-6 days a week) and is nowhere near being done. That very thing is what keeps me from building the ultimate (to me) backcountry flyer, I'd fizzle out long before completion.
I eyeballed the Highlander pretty hard at an aviation show last February, really liked what I saw. But I overheard the sales rep (I believe it was the outfit from eastern Oregon) tell a potential builder that he should be able to knock one off in about 500 hours, if he was handy with tools. Maybe he's right, IF you'd built a couple tube & fabric airplanes before. Judging from what I've seen heard, I'd guess it'd take something more like a thousand-plus hours.Maybe as much a two thousand, depending on how flat your learning curve turned out to be, and how deluxe you wanted the airplane to be.
If youd like to get out into the back country anytime soon, you might want to consider buying one (certiified or experimental) ready-to-fly. Maybe also buy the kit/parts for your dream airplane, and split your available time between flying one & building the other.
Eric