anyone got any advice or info on buying one? Im lookking to spend <$500, so this is meaning a used or refurbished one if I want something better than a sears POS. any brands to avoid? Features that are 'must haves' etc? my home gym will also consist of a smith machine (that I am going to be converting to a power rack), that has capabilities for pull downs and cable curls and what not... and a set of dumb bells hoping to have it all set up by thanksgiving, depending on when I can get my dad to bring the smith machine up from his house.