I would also be interested in how they can disrupt the results of blood/urine tests, I've had a few examinations with an AME since I started taking protein supplements and no issue has ever been raised.
And just to second what thebdct said, Myprotein in the UK are a manufacturer that offer unflavoured versions of most of their products. I also wanted to limit my sucralose intake and as all supplements (sweetened or not) taste awful anyway I opt for the unflavoured variety all the time.