Hi Iggy!

Most of those things (carb and fat blockers) either don't work, give you diarrhea, or are just plain unnecessary with low carb. You are already burning fat for energy and the fat you eat is poorly metabolized by your body for energy, so why the need to block it? Now...if you are eating a lot of carbs with fat, they might be helpful (although I have serious doubts). There are no "magic" pills out there. If there were, it would be front page news in every newspaper and medical journal out there.
Having said that, some people do use thermogenics (metabolism boosters) and you may find a good bit more information on that in the nutrition/supplements forum. They are not without side effects for some people, but others find them helpful.