As mentioned before, take whichever classes that are quantitative/analytical in nature that best suit your schedule. Two is enough.
Adcoms just want to know that your low GPA was due to lack of effort, not lack of brains. Also, they're not looking for math geniuses, so as long as you take a college level class in calculus, stats, finance, accounting, algebra, etc. and doing reasonably well in them, that's more than enough. You don't need to take some hardcore theoretical physics class or anything. Again, an alternate transcript is just about damage control - showing that you're no dummy.
Alex Chu
alex@mbaapply.com
www.mbaapply.com
http://mbaapply.blogspot.com