Hi Nugo, Hooray for manual mode! I'm glad to hear that you're interested in it.

A digital SLR is probably what your instructor has in mind. I've got the Nikon D100 and the Canon 20d. I love both of them for different reasons.
You can, however, adjust the aperture and the shutterspeed on many digicams as well.

Their aperture ranges will vary as well as their available shutterspeeds. Also the ease at which you can use them manually will vary. I've had a Nikon 995 for ages and its manual mode is simple to use. I'd suggest getting your hands on a few different camera models after reading product reviews and see which ones suit you and your needs.