I got the same shocks with the HD springs for my 750. I had to adjust the old shocks all the way up to keep the rear end from "swimming" through turns. I've got the Progressive shocks adjusted all the way down, to start, and the bike feels so much more solid on the road.
You can try adding some "pre-load" to your front fork springs to stiffen them up a bit. Large metal nuts work well. Progressive actually supplies short lengths of PVC pipe with their springs for this purpose. Just remove the top cap on each fork and add 1/2-3/4" spacer material(nuts,many washers,pipe,etc..). Getting the caps back on will be quite the adventure but you should notice a difference in the front end.