It`s actually not that many different plastic-kits. The basemodel is the Savage-Orc boss, the helmet is form the Orc-Boyz. 40K or fantasyrange, I believe the same helmet shows up in both ranges. Knee-caps are shoulderplates from tha marauder-box, which pretty everyone bought at SOME point of the hobby

All the other parts are from the Black-Orcs. This one box in particular is so incredibly versatile for conversions, it`s just unbelivable! You can easyly use their shoulderplates, gloves, elbowplates, kneeplates and sometime even simply cut off the leftover parts, like roundshaped spots for numbers, or the square plates for anything else.
Personally, I think I`d buy blackorcs for that one particular reason - they are a good well of parts for BB.