Tuarine is an amino acid and a metabolite of methionine. i have used the supplement magnesium taurate and really like it. its magnesium molecularly bound to taurine. best brand is 'cardiovascular research ltd' which you can get on amazon. they also have potassium magnesium taurate.
more info on taurine. its a critical part of one important bile acid the liver produces.
btw, have you looked into methyl donors and methylation? check out the supplement TMG, you might find that interesting. if you are dealing with mercury issues, then methyl donors are critical. i am only now learning about it so i am no expert, but its obviously important.