for the helmet on khezu D make sure that you have (1) Pale Bone, (2) Alluring Hide, (4) Earth Crystals and (2) Monster Fluids.
for the gauntlets, get (1) Pale Bone, (2) Alluring Hide, (6) Iron Ores and (1) Thunderbug.
if you want more rewwards, i suggest that you capture the monster so you can get the stuff you need on making the armor. the khezu D blademaster set is better used if you hunt along with other hunters since you'll have a wide area skill which will enable you to use items that can help boost the party's strength. if you're just collecting armors then id suggest that you get better ones instead of khezu D set or rank up first to unlock more rare items.