jrulier, your link did not seem to work.
The Minolta Flash Shoe Adaptor FS-1100 allows non Minolta flashes (ISO) to fit all film, digital and DSLR cameras that have the proprietary Minolta shoe. It provides these cameras an ISO type shoe.
However, it will not allow wireless control of other ISO type flashes, at least on the 7D and I doubt if your slave cell trigger will work.
Basically, the proprietary shoe is the same on the 7D, as it is on other Minolta cameras dating from after the 9000,7000 and 5000, but the signals from the 7D camera seem to be different.