Don't use a full frame DSLR for macro-shots. Beside the crappy codec and missing bit depth compared to the BMC the big sensor will result in a very narrow depth of field, as stated above. For that kind of work a smaller sensor comes in handy as it gives you a greater range of sharpness within the picture.
But there might be better choices than a BMC for macro work either, maybe you should go to a rental house, talk to them and rent something to try out what fits you best, if your budget allows this.
But don't go DSLR!
