OK, now we're getting somewhere.
I'll start off by clarifying exactly where I stand. I have taken both micro- and macroeconomics, statistics, and I'm starting business calculus on Monday. However, it seems that the top PhD programs want at least linear algebra and multivariable calculus, which obviously require more courses than I have outlined.
It seems that online math programs (at least past the calculus series) are rare, but I actually managed to find one at U of Illinois-Springfield. Anybody here dealt with them? Would they meet your definition of a reputable school?
Also, I've seen Texas Tech mentioned a few times on this board. Has anyone here actually dealt with them directly? If so, what were your experiences? Would you recommend that program?
I'm starting my IS PhD this fall, so I can't tell you how much maths is required. However, I think finance and economics (and maybe accounting?) may need more high-level maths than other specializations.
From what I know regarding the IS phd that I'm going to do, I can choose between the economics or OB track - the former requires more demanding econs/maths background that the latter. However, I don't think the demands are as high/tough as those doing econs PhD.
You may want to check through the schools' websites or contact some existing IS PhD students to find out more.