For planetary work, one widely used webcam is the Philips ToUcam pro--I've owned one for about two months. You can buy it at scopetronix.com (a vendor who has treated me well), including an adaptor to replace its lens with an empty 1.25-inch eyepiece barrel (easy, and it takes 30 seconds to do). Cost is about $150 including shipping. You will also need a good Barlow (and don't skimp on quality--bad barlows ruin an image. Think TeleVue--they sell nothing of poor optical quality) to magnify the image of Mars large enough when it falls on a CCD chip. I also use eyepiece projection, though the various adapters I use to accomplish this with the web cam may not be widely available.
For a digital camera, a Nikon Coolpix 995 is my choice. A year ago it cost $600 to $800. I don't know if it is still marketed. If so, the price should be lower now. Scopetronix.com had some interesting material on choosing digital cameras on their web site, and probably they still have it there. I have made roughly equally good pictures of Jupiter with the Nikon and the web cam. The web cam gives poorer raw images of them, but lots faster, so things even out with the square-root rule cited in my previous post. I couple the nikon to an eyepiece using the Digi-T system sold by scopetronix.com. They sell a billion adapters for various eyepieces, cameras, webcams, and so on. (Actually, my single best photo is from the Nikon coupled to a TeleVue Radian 10mm eyepiece, but the Radian itself is $250).