BCW shows usually feature Sabin, Raven, AMW, Team Canada, Douglas, Shark Boy, Dutt, D'Lo and others. TNA got Allistar Ralph from Team Canada from BCW, he was their champion, A-1(which is i think what they call him in TNA now.)
But they have never featured a NWA World Title match or Jeff Jarrett, which I'm guessing is just because Raven is a BCW regular and he happens to be the champion.
But I do think the BCW is good way to test the waters for TNA.