If 8051 is the choice then I can suggest a few speed ups. If now you are starting the hardware and artwork your are as good as failed. Get down to software design and programming based on readymade hardware available in your college. The readymade hardware can be kit like the Anshuman 8051 kit. It also has a SAR multichannel ADC card available, that too your college might have. Or a readymade SBC from SPJ, but that you may have to buy. Both of them come with good peripheral driver library and documentation.
Of course your professor in all probablity will shoot the idea down, but I hope you have developed the knack of overcoming that.
Then if time permits make the hardware in parallel by giving the artwork design to an outside agency or a junior in need of money.
Above all do not go to the sellers of readymade projects they are dime a dozen in this city and are conmen.
The AD chip may seem to be a easier option but ensure you can afford to buy a few in case you manage to kill some in the process of development. They may not be easily available or may be fakes.