How do you get video to play smoothly?
Generally I upload my videos at the resolution I record them in, which is HD720p at 'Normal' compression. My camera (Olympus SZ-30MR) also permits HD1080p at 'Fine' compression, but my Toshiba Satellite 650D laptop (AMD Turion dual processor) makes editing these a painful experience with all the stuittering in AVS Video Converter.
For less restriction when viewing the majority of formats supported in YouTube, you really need a PC with a core-duo processor. Mine is equivalent to an Intel i3, but since for you it will be a long-term investment, I would look for an i7 equivalent. They are coming down in price.
Streaming rates of course are only partially under your control, depending on what providers in your area will actually dish up, particularly when all the kids go on line after school.
Henry Falkner - SZ-30MR, SP-570UZ, Stylus 9010