DJ is shown together with Gear 2 and 3. If Sanji has equal power as Luffy, DJ should have attack rating and attack speed of both.
IJ is shown together with Gear 4 completed. If Sanji has equal power, IJ should be as fast and strong as Snakeman, Boundman, and Tankman.
Which means, IJ overall should be near Gear 4, or on the lowest limit of Gear 4.
Practically, IJ Sanji can beat Doffy among the arc/luffy's main villain so far, while Cracker is questionable due to the food stuff.