hi, i hope i'm in a right place to post this.

I'm currently choosing components for my bike's drivetrain, as my ones are worn out.
my current triple setup is:
cranks - fsa vero 175mm 52/42/30
cassette - sram pg 950 12-26
rear derailleur - shimano tiagra 9sp long cage
front derailleur - shimano tiagra 9sp

i'm currently thinking about gaining more speed (when riding down the hill) and getting rid of granny gears which i almost never use (the 23/26 cogs). so the parts i'm considering are:

cranks - FSA Carbon Pro Team Issue 172.5mm 53/39/30 Octalink (with 60% discount)
BB - Shimano Dura Ace Octalink 7700(7703)
cassette - help me decide. currently thinking of dura ace 11-21 or sram pg970 :/ sram is somewhat cheaper, but don't know about the weight.
chain KMC X9 (any better chains?)
should i also look for a new front derailleur to fit 53 chainring, or the current one will do the job?
should i buy long/mid/short cage rare derailleur as i am getting rid of 2 largest cogs and i never use crossover gears? if it is short cage i'm thinking of Shimano Dura Ace 9 Speed 7700.

are there any better alternatives for any of these parts from sram or campagnolo?
any of these parts incompatible with each other and is there anything else i should think about?