Since you have the CYMA I'd recommend doing basic reliability mods first,mainly compression since you want good range. Do note that range upgrades and accuracy upgrades go hand in hand,unless we're talking about how far you can overhop your round to space.
Dual O ring cylinder head,Oring nozzle,AOE correction,shimming,etc.. Polishing your cylinder is also a good idea. Grease it up well too.
For a barrel PDi is the best,but Laylax will feel the same since you will be firing with bursts and not single shot,it really depends on how much you want to spend.
With buckings,Maple leaf is good. PDi W hold is good too but has trouble lifting heavier rounds. G&G green is what i generally use since it's cheap and good.
Stock CYMA hop unit should be fine.
You can do flat hop,G-Hop or R-hop,I can only say that G-hop isn;t super hard and works well if you use good bucking,G&G's ones are good for this in my experience again since my old craft knife liked them more
Honestly I'm out of the loop tech wise since I've reduced chairsofting by a fair bit.