Well, I found that the Maxim 3000 series to be pretty helpful. You mention something like the 74HCT245. I am not sure what you mean by each having its own individual control, but maybe a group control? Have a look:

http://datasheets.maxim-ic.com/en/ds/MAX...AX3012.pdf

Perhaps, this could potentially help? So far, this is one of the most compact and best choices for bi-directional data traffic that I have found. It also includes multiple voltage translation circuit topology, you are not restricted to just 3v3 and 5v. I have yet to try this one out though. They have a guaranteed data rate which was one of your issues, but the current to drive ribbon cables may be too little, as mentioned earlier. They do have a separate applications manual that describes the evolution of this chip up to this point that would be beneficial if you wanted to create your own circuit.

Found the link:

http://www.maxim-ic.com/app-notes...vp/id/3007