I currently have an 200amp panel with only one open space and I am in the process of finishing the basement. I was looking to install an 125 amp subpanel with 8 spaces (16 circuits) to use for the basement and future outdoor projects including a hot tube. Will this size subpanel do and what size wires should I use to feed it from the main panel? Will I need to run a new ground wire for the subpanel to the water pipe or can I extend the ground and neutral hook ups from the main panel to the subpanel? The subpanel will be a couple of feet away from the main panel. Thanks for the help.

My garage is about 35-40 feet behind my house. Right now there are two 12/2 with ground romex lines burried, carrying 120V to the garage. I would like to add 220 for use of a welder and compressor. What I am thinking is adding a double pole 30 amp breaker to my panel in the house and running 8/3 with ground UF wire (burried in the ground) to the garage, going to a twist lock receptale. Does this sound like a good plan? Thanks, Shawn