CCD Camera design

Hi

I want to build my own astronomical camera. I don't have decided which
I'll use. I want to put a color CMOS sensor but many web sites relates
that CMOS sensors are not very good (high dark level)
I've seen a color CMOS sensor with 1,3 Mpixel (1280x1024) at a very low
price (about $140).

For best performance, do I use a color sensor or B&W sensor ? In term
of sensitivy, dark noise which is the best (colour or B&W)?

Cordially

Alain