Hex and C play nicely together.  Hex even has a "save as" Carrara type file option which makes going from Hex to C very easy.  Unfortunatly it does not read C type files.  It does read OBJ files and it also reads Amapi files.  As for modeling, Hex is like the C vertex modeler on steriods.

It has been a long time since I used Bryce, but I believe it does read and save OBJ files.