I have never had torrefacto, but I have had burned sugar and it isn't my cuppa. Sumatra is excellent and the next best cheap alternative to Jamaican Blue Mountain (with lower acidity and greater body when freshly roasted.) Actually nothing really compares to JBM, but Sumatra is still excellent.
Here is an article that is obviously biased against torrefacto, but it does appear to have some interesting history of the sugar roasted practice:
http://www.madridchow.com/the-curious-ca...

When I can find it, I buy Sumatra green coffee beans and roast them either in the oven (carefully) or in a hot air popcorn popper (easier and less likely to burn the beans.)
Here in Atlanta area the Dekalb farmers market has only Colombian and Kenyan green beans at $5-$7/lb. The Kenyan are too harsh for my palate, but the Colombian are fine. Not Sumatra, but acceptable. I haven't ordered online yet, but I may place an order now that you have me looking.
Here is a discussion on ordering green coffee beans online at CoffeeGeek:
http://coffeegeek.com/forums/coffee/home...
and here is one of the recommended stores' Sumatra:
http://www.happymugcoffee.com/en/green-o...
and another store's Sumatra:
http://www.u-roast-em.com/coffee-beans-s...

I have also enjoyed coffee from Brazil and it is often the least expensive for making a good espresso. Might be worth ordering a few varieties from different growing regions just for the experience.

You may wish to visit Sweet Maria's (sweetmarias.com), whence you can buy all of the green beans you would like from various parts of the world. (I am surrounded by self-roasting connoisseurs of The Bean).

Jan