I'm planning to get my calipers powder coated pretty soon, my question is, Do I have to rebuild my calipers when I remove them from my car? Or can I reuse all the seals and dust boots? Afer I get my calipers back of course

I was about to ask what condition the old ones are in... But really, the seal kit is dirt cheap, so if you're taking them out, replace them.

The old seals get pryed out and there is a chance they could get damaged in the process. As mentioned the seal kits are pretty affordable, especially if you go with the Centric ones. Here is a link to a write up I made on how to rebuild the calipers. Hope it helps! How to Rebuild and Repaint Brembo Calipers - DirtyEvo.com