rich is right the sp2 and spII have the same spec overall
they are better suited for sli if you are interested
and the smart powers will work fine if you do not use sli
you mean Truepower 2 (TP2 and TP-II)
Actually, it goes like this from best quality to good.
NeoHE is their flag ship brand, triple 12v rails, modular.
Truepower is their preformance
Smartpower is for budget-minded folks.