Daniel Defense makes fancy inserts to bring your smaller light up to 1":
https://danieldefense.com/mounts/off...nsert-835.html
But really, tape is going to work fine, too.
This is what I use for a mount. It's kind of pricey at $50, but then again when you compare to Surefire, it's a steal, and really, you can swap out your lights when you get better ones or new technology comes out:
https://danieldefense.com/mounts/off...ght-mount.html
However, you don't even need to go as fancy as that, since you can just use Weaver rings like you are saying.