In reply to damowilk:
This is not upgrading, it's maintenance !
Some suggestions:
Forks: What the heck is the LBS doing suggesting MRP Ribbon coil forks for this bike?
Your bike has Reba forks at 100mm?
Have a look at Rockshox Revelations, Yari, Pike. Choose your wallet point. Yari/Pike, probably too much for this bike, but could make it fun. RS are low maintenance forks.
You can get 120mm variants on all of these (the frame is rated up to 120mm at 650B):
https://www.sram.com/rockshox/component/forks#sm.0001co8vof58udwhsht2dhudu8...
If you are contemplating using the 29er wheels, need to make sure any fork upgrade can accommodate them (the frame is rated up to 100mm at 29er).
Brakes: splash on some SRAM Guide RSC.
Upgrade to bigger rotors, go for 200mm if you can front & rear. You can never have enough braking power
Cassette: have a looks at E13 9-46t (runs on 11sp SRAM); been running these for a good while, love the range (bigger range than Eagle), but not cheap. Should allow you to go 34t at front, or an easier life at 32t?
Derailleur: stick with SRAM, GX a good compromise and these things prone to damage.
Chain: replace as soon as worn, don't be tempted to keep running.
Definitely try a dropper. But Reverbs just don't last, I can get through one in 9 to 12 months. We had three go at the same time last month! (only one under warranty)
Just put an X-fusion on the hardtail, meant to be OK, we'll see. My partner has just put on the E13 dropper (X-fusion body too long for the frame), again we'll see if they last.