Ali parts will work just fine. Got 2 bars from them, one is a integrated one for my XC rigid singlespeed with 600x120mm(yes oldschool) and a 760mm for my trailbike. The integrated one weighs about 259g afaik. thats for the bar and the integrtaed stem. didn't weigh the 760mm one though.
I also got one BXT carbon saddle which is stated to be at 65g(not sure but that but surely under 100g). A bit narrow, but way more comfy than one might imagine cause it flexes a bit. Proably not the prettiest one, but it works and weighs nothing