I wanted to change out my electrical panel as it has the old push button circuit breakers and increase the physical size of the box for a few reasons.

I believe the house is on 200A (2, 100 amp breakers outside linked together)

1) Half of the house is not grounded, thats how they did it back then. Newer parts of the house are

2) I think I am maxed out on circuits and I need more room to add lighting, outlets etc...

3) I want to put a few outlets and security lighting outside and around the house using 12/2 wire ( I would presume in my outside electrical plan all outlets and light could be on one breaker as long as I don't exceed the amps)

4) As I remodel and update the house, I need to replace the wiring in the home that is not grounded and rewiring the whole house just may be a single project

5) I need to finish my laundry room but I can't sheet rock until I do something with the panel and everything above so I don't tear it out later

Now here is my question

Would it be easier to run all the NEW wire into a new location for the electrical panel ( I would have to extend the feed line from top floor to basement either junction box or a full line) - Junction box would be cheaper. Then essential each plug/light outlet would have 2 wire feeds, the old one, then the new one and once I get everything wired up, I can switch it over.

Or use the existing box location, replace the breaker box then start to re-wire sections of the house and run the new wire to prepare for hook up into the new box