In the main part of this paper we project forward to having B factory determinations of sin (2β) and sin (2α), for which we take several values. First, we use a joint χ2 analysis of CKM experiments to constrain CKM matrix elements in the standard model, and experiments on the angles a, β and γ, and on xs and null CP asymmetries. Then we invoke mixing to a new isosinglet down quark (as in E6) which induces FCNC’s that allow a Z0 mediated contribution to [Formula: see text] mixing and which brings in new phases. We then repeat the χ2 analysis, now including experimental constraints from FCNC’s as well, finding much larger ranges of prediction for the B factory. We then add projected B factory results on sin (2β) and sin (2α) and repeat both analyses. In (ρ, η) and (xs, sin (γ)) plots for the extra isosinglet down quark model, we find multiple regions that will require experiments on sin (γ) and/or xs to decide between, and possibly to effectively bound out the extra down quark contribution.