If you are the only employee of the S-corp and the business income is predominantly from your labors then the wags you are paid should be probably in the 90% range of the income brought in no matter what the average rate for this position is else where. Just because you can make more working for yourself doesn't mean you can avoid SE/FICA taxes by taking an artificially low wage.
However this is not something set in stone ... so pick an amount you could support if audited but also expect to lose if challenged.
