Welcome to the fun world of FE Boats. There are alot of ESC's out there. The Hextronik HXT 120, Castle Creations Hydra 120 and 240, Pulso 100 amp, shultze esc's etc. You can get these from Unitedhobbies.com, Offshoreelectrics.com, finedesignrc.com etc. Good forums for info. would be here, Offshoreelectrics.com, rumrunnerracing.com. To calculate amp draw in general and estimated speed, use fecalc. Do a search on google for that. I don't remember where to get that off hand. I think it is at rcboataholic.com. I hope this helps and keep us posted on your build. Sharing of gained knowledge is also what makes this hobby fun.