It would help to know what stats you would like on it. Do you want more Aim than Endurance, Crit, Power, etc...?

While levelling an orange helmet (and the rest of gear) might be a better choice so you can upgrade it as you progress. A level 25 green may end up being better than level 16 purple.

Post 1.2 the answer is definitely yes. You will be able to take out the armouring/hilt/barrel, mod and enhancement from any purple artefact gear and place it an orange piece of gear, which on top can also have an augment slot, thus making the final piece of gear better than the original artefact piece.