James, 2 quick suggestions:
2) For day-to-day use, you really want to boot/use USB. I have a 128G USB stick, and no uSD card. I have been burned too many times, even with quality uSD cards. They're OK to boot with, and in fact, recommended. But once everything works, USB boot is best (stick, or HD if you power supply is big enough).
There is some malarkey you need to do to be sure the 3+ is configured for USB boot (goog for details), but 2 of my more recent units were ready-to-go with USB boot.
There's no real advantage to 64-bit OS that I can see for RPi3. (Although I do run aarch64 on a few RPi4 units w/8GB -- also via USB boot)