Here is a picture of a dual-26 SWB. The seat is as low as possible for such a bike -- even short people can ride it. However, it is more of a high racer than low racer.
http://www.nazca-ligfietsen.nl/model...ike=pioneer_bs
http://www.nazca-ligfietsen.nl/nieuws/
If you want a low racer, then I'd build on dual-20s for the quick handling.