Are you looking for someone to come help you, or are you starting a project thread for advice?
If the former this is the right place for it, otherwise the Large EV section is probably better, and I can move it there for you.
I'm not sure which controller would be best for your project; we don't know how much power you need, or what kind of features you're after. There are different ways for a controller to drive a motor (square/trap, sine (lookuptable type), and FOC, for instance). There are other features such as forms of electric braking, or the ability to send info to a dashboard display and/or receive commands from one, or various types of control inputs, or safety features, etc. Some may have better autotunes (for FOC types), or more parameters you can manually tune, etc. Often the more things a controller can do, the harder it is to setup and the longer it takes to get it matched up to your needs and system (Sevcon as an example)...but the more perfectly you can match it to your setup and not have to limit your project because of things it can't do.
If you don't already know how much power your system will use to do the job it has to do, I'd recommend sitting down and making a list of all the conditions, terrain, speed, weight of system, wind, etc. that the buggy has to operate in and at, and use that info in simulators or calculators such as those at ebikes.ca to guesstimate how much power it will take to do that job.
FWIW:
From the many forum posts about them here, Sevcons don't seem to be easy to setup even if you already have the right files for the specific motor you're using, as you still have to setup all the options to match your other system components and wiring, and the hardware and software to set it up is not cheap, either. There are companies out there that sell services of setting these up for people, for that reason; I expect those services are also not cheap.
Kelly has some controllers that can brick themselves if you spin the motor while it's attached to the setup software/computer; there are notes in the manuals for these, such as this one from the KLS manual (AFAICR it's also in the 8080):
"Anyway please try to do identification angle operation before running the motor.And please don't try to connect the controller to user program while the motor is still running,letalone change the setting in user program or Android App.That is to say,if you want to connectcontroller to user program or try to do programming,please stop the motor first.This is the most important thing."
Where it *should* be created so that problems from that can't happen, and/or it detects any conditions that will cause a problem and prevent operation of the setup program.
