First Car Ideas
A lot of people's first cars were Dusters! My first car was a '74 Gold Duster in Ivy green. Just a stock 318/904, but I loved it! It didn't have power or anything going for it other than it was my car, and that was enough. That was 20yrs ago.
Now, my son is 14yrs old, and this past year we picked up a '70 Duster for him. It was a 318/904, but we decided to throw in a mild 360/4spd with 3.55 gears out back. Nothing to powerful, but enough to have fun. I figured I'd put it together the first time, and when he gets out of college, if he wants more power, we can build up a stroker.
Personally, I would caution against a lot of horsepower. Even if you had 20yrs driving experience, you still run into issues with drive-ability, economy, break downs, over heating, excessive rear tire wear, etc..
A legit 300-350hp small block will be more than enough and be trouble free for many years.
Racecars make poor daily drivers.
Either way have a blast.