First of all, I commend you for taking up filmmaking in your retirement years. It’s a rewarding activity, whether it’s a hobby or a profession. To your questions:
You will most likely get more power out an 8-core Haswell. As far as the video card goes, the K2200 is a little long in the tooth, but still a usable card. However, more power can be gained using the high-end GeForce cards that you listed, as they contain more CUDA cores than the Quadro. You can get higher-end Quadro cards as well, but the get very pricey very quickly, the higher you go. The main difference between Quadro and GeForce cards is stability. Quadros are meant to be used for longer periods of time without rest and remaining stable, without glitches. GeForce cards are meant more for playing games in shorter spurts of a few hours, but give you more power because of what they’re made to do, but may become unstable if used for too long. However “too long” is subjective. I use GeForce cards, and they last me through a 12-hour day without issues. I would say save the money, and get more power with one of the GeForce cards.