So I made the mistake of upgrading to Yosemite and I can't revert back to Mavericks. I bought this SSD and am trying to clone my HDD. However Carbon Copy says it does not support Yosemite, are there alternatives to Carbon Copy ?
I had the same problem, as you. My advice is simply copy all the needed personal files (photos, videos, working projects, documents) and format the HDD. Then reinstall the system (clean). Everything should be OK, you can always download deleted apps from App Store, so you don't need to backup them.
Yes. Mac Backup Guru will make bootable clones of your disk, and runs in Yosemite.
"Mac Backup Guru has 3 main functions: Direct Cloning, Synchronization, and Incremental Snapshots."
It also has a free month long trial that you can use. That should give you plenty of time.