Building a Spectrometer

So I am building a spectrometer in my college, it would be small one just for taking spectrum of our sun. I had some doubts related to instrumentation and data calibration.

1. Which detector should I use CCD or CMOS? And if CMOS then will the webcam simply work or I need to buy a scientific CMOS
2. What calibration method should I use, Emission line calibration (basically calibration lamps) and then polynomial fitting or using a laser of known wavelength?
3. Does size of diffraction grating affect the spectrum received?

Please answer these. Would be very helpful.