Given the reworking of the plumbing for the water supply that you will encounter switching to a "conventional" tank-type toilet, your options as to which brand/model you switch to are pretty much wide open provided the rough-in for the drain is the same. Rough-in is the distance from the center of the drain to the finished wall. If measuring with the toilet in place, measure from the bolts that hold the toilet bowl to the floor back to the finished wall. The most common rough-in is 12 inches, although there are also 10 and 14 inch installations. Many manufacturers offer their standard models in all three sizes. Toto has several models which can be adapted to variable-sized rough-ins with an appropriately sized Unifit adaptor and Niagara's Flapperless model has flexibility in the tank installation to allow for 10- or 12-inch rough-in.
Considering that the correct plumbing is already in place, I personally would stay with the Flush-o-meter. They appear to be less prone to clogging due to the increased water pressure in the flush. In this case, I would be willing to allow functionality to override my fashion sense in terms of how it looks.
