Tom, I sent you a private email with some other recommendations.
But for your specific question concerning SLA's it has been my experience that you rarely get satisfaction as a result of what is in the SLA.
What matters more is
1) are you considered a good customer or just another "small fry" operator?
2) are the folks running the place competent and flexible, or are they bureaucrats?
Bandwidth pricing is all over the place, but a T1 from Internap (pretty much the best there is) is less than $900/mo most places. So figure 300GB as a typical max monthly usage and you have a base rate of $3/GB. Plus power, space, profit, etc. Of course, the company you are dealing with is buying much much more than a T1 and therefore getting a better price.