Is it level 32 or 35? Thanks

I may be wrong, but I think it's 46 for ALL THE set being maxed.

Correct me if I'm wrong.

This is correct.

You need to be at least on level 32 to get the best version of the armor.
However, at this level you will only get the third tier of Nightingale weapons. The best, fifth, is awarded at level 46+. If you don't want to wait that long, I'd recommend being at least at level 36 when acquiring the weapons - it's the requitement for fourth tier.

Remember though that the blade is bugged at its max level - you cant upgrade the 46+ version via smithing.

yep so it comes down to do you wait til level 46 and get the best suit and a bugged blade hoping they fix the blade (im currently holding a wall hanger) or time your level so you get the blade at level 45 then level up to 46 prior to getting to the spot in the quest line were you get the armor.

what's the weapon lvl before that? 42? seems like a good compromise... (if you're not too obsessive about it).

edit: Wait, it's 36-45. And the difference is negligible. 14 vs 15 dmg, and 20 vs 25 absorb effect.

36-45
000f6526 14 1920 13 3000/320=9 Absorb 20 points of health:

• http://www.uesp.net/wiki/Skyrim:Absorb_Health, 20 pts for 1 sec
  
• http://www.uesp.net/wiki/Skyrim:Absorb_Stamina, 25^? pts for 1 sec

46+
000f6527 15 2450 14 3000/381=7 Absorb 25 points of health:

• http://www.uesp.net/wiki/Skyrim:Absorb_Health, 25 pts for 1 sec
  
• http://www.uesp.net/wiki/Skyrim:Absorb_Stamina, 25 pts for 1 sec