Aiden, WELCOME TO THE FAMILY!!!! Love the car!
Here's my 10 cents (my 2 cents are free). I started out with a 289 in my 1965 (Peg). I did all the go fast goodies stuff (intake, carb, cam, exhaust, MSD, etc . . .). It was a lot of fun building that little motor up over 18 months. To get me through college (I was 16 when I got her), my parents insisted on a "reliable engine" because I was driving 5 hours each way to school. So, they had a "pro" build a 351W that was solid, reliable, and not that "racing motor".
So, the guy IS a pro, and that motor was head and shoulders over the "hot" 289 I had. It was a different world, okay? If you REALLY want some fun power in a fun car, as much as I love the little 17 squared motors (AND I DO!), for a street car, it's just tough to beat some extra cubes for about the same price and problems. You can get fun out of it without having to turn up the rpm's, they don't work as hard, and it doesn't cost much more (if any). Just something to think about . . .
Oh, got out of college and that "pro" built another Windsor for me . . .409 stroker . . . solid lifter . . . beast of a motor . . . in 1994. That same motor is about to get a Tremec TKO, I think.
Go with the Windsor if you can.