Standard gear for all and T'Challa gets the ebony blade. Random encounter. T'Challa and Killmonger will be working cohesively for purposes of this battle. Oh, and T'Challa is heart-shaped herb levels.
Current standard gear for black panther? I say black panther takes steve due to better gear, If Buckey has guns he probably beats killmonger, all though hand to hand I think killonger beats buckey due to his monstrous stats.
Here are some killmonger scans if anyone is interested:
I think it has been stated that killmonger is familiar with black panthers fighting style. I just figured I should note that just encase.