just to throw the cat amoungst the pigeons here.
consider servodrive and motor it may prove more economical.
these days the pricing is competitive
I did read 60hp
Up to 30hp 1800rpm, you can use a TENV motor but this app is at 60hp so the TEBC motor would be the choice if the zero speed dwell time was more than a few seconds or the duty cycle was more than about 5%.
Although the ACS800 is a good drive, I consider it to be too "mature". The ACSM1 and the ACS850 are better choices that will be around longer. Yes, an encoder is a must for this application.