I would consider FOCBOX (aka vesc-x) as an option. I havent seen that many emtb builds with it but im sure there should be some… it will of course cost more but at least theres gonna be more finetuning…
Though from what ive heard if you want to feel the ‘dirt bike’ experience, then it is better not to choose vesc but take some of the higher output ‘regular escs’
I dont have calc data at the moment, but with 200kv your speed might be very close yes, Ive calculated myself that 213kv motor would be the best for 6s and ~40kph speeds but these 213kv motors are hard to find.
Im running 4:33 ratio, with 9inch wheels, 192kv motor and li-ion 6s battery, I think I can get about 36kph… havent really measured final speed, as it might depend on battery level a bit too… but it is above 30kph for sure.
Maybe @Duffman himself can chime in, perhaps he has went through a few escs to tell you the difference on what to choose the best.
As final note, if you can afford not to go with cheap 6s esc, I would advise to aim for at least 8s setup, Im pretty sure the feel might be way different. Though, try to collect some more info as I have very limited experience on how other setups feel besides my own but I know I dont really have high power setup because of limited voltage / esc.
At 21.6v (li-ion) if you push about 80A, you can get ~ 1600W of power.
With 28 / 36v This number drastically increases close to / over 2000W of power.
You might not need it for constant riding but for acceleration boosts, wheelies and what not, this power can be very useful.