Although I am by no means an expert on the matter, I have heard that switching programs requires a delicate explanation as to why there is a desire to change "mid-program", which may be more so in your case due to the similarities in the programs and the potential overlap in career options.
I know of a few people who are getting their PhD in Mathematics but doing their dissertation in statistics and taking more statistical classes, so I agree with the point Applied Math to Stat made that it seems feasible to accomplish similar things with a Mathematics PhD.
That being said, if you really want to switch, I'm sure it's not unheard of. I would consider taking the GRE again, and emphasizing your research might be good approach. The schools you are looking at don't seem unreasonable, but as it was explained to me, they turn away a lot of 4.0 students in favor of those with "research potential" (often represented through letters of recommendation) and those they feel will pass the qualifying exams (at least partially represented through the GRE).
Best of luck in whatever you decide!