Erie Trib Steelies
I think your steelies don't run too large, with 4 to 5 lb. fish average. (At least, that's my experience with steelies from Lake Erie.) I use a couple of rods, a 6-wt. and a 7-wt., and both rods work well. A good 6-wt. with backbone may be of advantage, because besides handling the steelhead chores and bass fishing, you can use it for smaller stream trout without it being "overkill".
The 7-wt. would also be a good choice, however. It really depends on how much of each type of fishing you do.