WELCOME TO THE FORUM!!
I was going to take a couple of pics with that lens and with a couple of different teleconverters for you when I remembered that I loaned it to my son for his Disney trip (he left last night).
I have Sigma 1.4X and 2X teleconverters and a Tamron 2X and I know it works with all of those. I don't know if it works with the Canon teleconverters, but if it does, I think they would produce the best results. They would also be the most expensive ones.
Your Rebel will lose AF with any teleconverter on any lens that has a resultant apertature of f/5.6 or smaller. A 1.4X will result in an f/8.0 and a 2X will result in f/11, so you will lose the AF.
If you'd still like to see some results in about 10 days, let me know.