Hi, I will be using the Futaba S9352HV due to it's high speed and good torque. I could not find more details regarding this servo but according to the sales guy, he states that this servo is capable of continuous rotation, however, positional control is no longer possible via the built-in servo driver
Given that this "sales guy" stated "this servo is capable of continuous rotation" - it would seem that the servo being sold isn't sold pre-modified. You would have to do that yourself; there are plenty of tutorials out there that explain how to modify a servo to make it a continuous rotation servo. Once you do so, though, you will lose any means of controlling it's position (since it essentially involves disconnecting the internal potentiometer from the gearing, so the motor controller inside the servo no longer has a positional reference signal).
- hence it may have to be via from my own servo controller, which in this case will be the Arduino.
Yes - you would have to come up with a way to monitor the position of the servo, and when it was positioned properly, stop it (or set up a PID controller to gradually bring it to a halt).
I would like to have 2 revolutions with positional control (eg stops at 0, 90, 180, 270, 360, 450, 540, 630 and 720 degrees). I would like to ask if this possible to configure using the Arduino?
Yes, you could do this - there are a number of ways:
1. You could gear down the output shaft and connect that reduction drive to a potentiometer (maybe even the one from the servo, if you are able to carefully remove it).
2. You could attach a multi-turn potentiometer to the output shaft - there are many inexpensive ones, but most are limited to 10 turns or so.
3. You could attach what is called a "servo potentiometer" to the output shaft. These are potentiometers that are continuous rotation devices, which have a small "dead band" gap at one point in the rotation; they tend to be precision devices, and rather expensive new. If you can find one used or surplus, you'll pay less (but again, depending on where you buy them and the brand, "less" might still be seen as expensive).
4. You could attach an optical absolute encoder to the output shaft - note that this will likely be the most expensive option, depending on how many bits the encoder is (the higher the number of bits, the smaller the minimum rotation angle you can resolve will be - ie, an 8 bit encoder will give you 360/256 degree resolution, a 9 bit encoder will give you 360/512 degree resolution, etc).
All this said - that is a lot of money to spend on a servo that you are going to void the warranty on by opening and modifiying - to essentially turn it into a gear motor that you have to add your own position control back to. You might want to explore getting a standard DC gearmotor with similar torque specs, and a suitable h-bridge to drive it. At least, take a look into it - you may find it to be a better deal (or you may not - but at least you'll know).