Help me buying handlebar, stem and seatpost(no dropper)

AndresTwoSix
AndresTwoSix Posts: 2
edited January 2016 in MTB buying advice
Sorry if this topic is already discussed, I was wondering which stem handlebar and seatpost for my 650B hardtail are the best in security, weight and resistance.

I have in mind the 3T Doric team seat post and Arix-Team stem with 3T team handlebar.

One friend of mine said that FSA Afterburner Kit is doing a great job.

I want a Flat bar but I also need to think in the change I will do, I am currently using 580mm flat handlebar with 27.5 diameter and a 110mm stem. Those are pretty heavy, those are the ones that came with the bike. It's an Scott Scale 40 2008", I changed the 26" rims to 650B Mavic CrossRide and I am wondering which kit will be the best in my case.

Also to mention, I usually ride XC and a little of light trail in that bike.

My height 179cm. Leg length 80cm.

Also I think I would need help buying a new XT M8000 transmission
I think in getting the 11-40 with OneUp 45T extension and 34T chainring
Or getting the 11-42 with 32T chainring.

My last option is to get a 2x system from XT M8000.

In this moment I don't know which crankarm will be the best for my height and leg length.

The last question. Is it best to get the lever with I-Spec II or the one with the monitor. I already have the M8000 brakes with I-Spec II.

Thanks!