Welcome to TRT!
For coral, it's not too hard to find aquacultured and maricultured corals, and surely there are a number of clubs in your area, where folks are often eager to share their
coral frags (there are tons of websites to get frags, and check out
www.liveaquaria.com, in their Diver's Den, for cultured coral).
In terms of fish, there are only a few species that are tank bred (like clowns, as you mention), but for the most part fish are wild caught. There has not been much success at raising some of the more popular fish, like tangs, triggers, etc.
For LR, you can easily get or make artificial rock, after which you only need a little LR (rubble from a local hobbyist) and some patience to turn it into all live rock.
Good luck on your reef setup, and kudos for being concerned about your impact! Of course, don't start thinking about the electricity required to run some of the equipment, or you may rethink the whole thing all over again...