Having used Kona, Matrox and Blackmagic with FCP my preference is Kona and agree with Steve the LHe and LHi are probably your best options.
The LHi offers extra connectivity in that it in addition to the standard HD and SD BNC connectors it also has HDMI
It also offers the option to upconvert, downconvert and cross convert.
The LHe is a similar spec but no HDMI and only offers downconvert.
Obviously the breakout boxes for each reflect the neccesary io connectors.
best wishes
Neil
http://www.patience.tv