Quamen/CamAcura/Nankai doesn't make completes. The three brands are what remains of Japanese company Dig It that used to make the ultra-popular Graveyard OG bars - now sadly discontinued, but Quamen makes some really bomber flatland bars of their own. Sick Child is one of the last remaining American frame and fork makers still very much devoted to flatland (instead of most American companies with one half-assed flatland or hybrid street/flat frame in addition to a full line of street and dirt frames), but they don't sell completes. Ares does sell completes, and some pretty nice ones...mostly equipped with parts by 88 Products (same company). Some companies produce complete flatland bikes that aren't available in the US, only in Japan where it's a lot more popular. Fly is sort of an exception, being a primarily street/park driven company but still putting time and effort into developing respectable flatland frames which are also available as completes.

If anyone can read Japanese, Dig It is still around but I'm not sure exactly what their function and relation to the splintered brands is anymore.