It doesn't matter whether the airplane is storebought or homebuilt; a
complex airplane is a complex airplane -- and the one you're
describing isn't. It needs retractable gear, flaps and a controllable-
pitch propeller to be complex. It doesn't need more than 200 hp --
that would make it a high-performance airplane, requiring a different
endorsement. But you'll need the appropriate endorsement(s) to fly a
plane regardless of its registration category.