Where to Start

I have a 1968 Dart GT with a /6 with 9" drum brakes. The /6 runs fine. But, I want to do some upgrades.

I have enough cash this year to do either a "used V8 and used 727 and upgraded rear" or "I can do knew front disc brakes and suspension all the way around".

The car is going to be used once or twice a week for 15 to 300 miles, 6 months out of the year, as a weekend driver. NO Racing is planned. Just want to drive the wife or the kids around and maybe to the beach, my oldest may drive it on the weekends, she is 20. Brakes first and motor next year or motor this year and do the brakes next year? Where to start?

If motor first, any concerns about stopping with the small brakes?