Low light portrait photography is awesome and good luck. But first let me tell you that the money you spend on a low end camera with low end glass will = low end photos. Eventually you will buy the right stuff and wished you never bought the crap gear. Save your money and get something legitimate. I would reccomend something like the Nikon D90 or D7000, if you are looking to stay low cost but still do professional quality work. I would sugest nice fixed prime lenses for portrait photography ie 50mm or 85mm 1.8 or better. Buying used is great, ppl upgrade all the time and finding good used stuff is cool. your questions: 1. no, 50mm 1.8 or 85mm 1.8 or better 2. depends how dark the lighting is 3. a 16 GB 10speed SD card holds about 4k pictures in fine/small jpeg format, perfect for 8x10 photos 4. tripod is a must for low light along with a remote Hope this helps!