If you are buying new from one of the folks above, they'll help you determine the wheel size you need. You want to buy a highwheel that looks as much like an original as possible. Good replicas keep that small clearance. Bad replicas have two or more inches. Originals were trying to keep the cycle as compact as possible, and also make it easier to get into the saddle.
Poor replicas use a single sized tube the whole length.
A spoon brake with a lever that follows the curve of the handlebar. Shame on you. A leather seat, mounted close to the backbone. The worst replica design uses a modern seat, held in place with a peg welded or brazed to the backbone. Most replicas use modern sealed bearings, but the Spillane duplicates an original-style bearing case.