Tenor guitar strung in a fourths-based tuning (DGBE, ADGC) and not fifths sounds much more like six string guitar, it’s how I usually tune mine. You can go full electric on them too.

Cigar box guitars can sound pretty damn good amped up as well, and are often much cheaper to get. I picked one up from this ebay seller almost a decade ago, and still enjoy playing it. He might only make three stringers now, but those are even easier to play. Or if you’re handy, you can even make them yourself.