High eRPM Speed Controller (ESC)?

Hi I have a couple of Turnigy Rotomax 50cc & 100cc motors I need to get running.

They will be installed on a modified kids go-kart (with a grown-ass man riding it) with a small 8 inch drive wheel. Low down speed is highly important but the best gearing is about 12(motor)-70(wheel). No space for more gearing.

I'll have to add Hall Sensors for Sensored operation.

I'm wondering what controller will suit? Please recommend!
Do I need to worry about controller sync issues with a very high eRPM?

Motor Specs Rotomax 50cc / 100cc:
KV: 172Kv / 167Kv
Poles: 24 (maybe 28?)
Volts: up to 50v / 60v
Amps: 120A / 170A
RPM: 8600+
eRPM: up to 100,000!

I have just blown up a Castle Creations HVF160 ESC on the 50cc @ 50V since the sensorless operation causes current spikes on acceleration from stopped. ...and I just kept hitting the throttle after every current limit reset

Just saw this.. Check out nucular controller here on ES. It should do 100kerpm and users seem happy.