In that circumstance I like a 7' med or med light fast action graphite spinning rod and 4 lb test mono. If that's not heavy enough for your tastes - 6 lb line max. It's what I've used on large rivers out west for trout and smaller steelhead for many years.
I prefer fishing 4 lb line and paired with a reel with a good drag I've caught steelhead up to 12 lbs. 5 to 8 lb steelies day in and day out is no problem with a set-up like that.
A couple of years ago I added another rod to the collection that IMO would be perfect. It was an inexpensive Quantum Affinity 7' 2 piece AFS702MA IM7 graphite rated for 6 to 14 lb line. It fishes well with 4 or 6 lb line. It's not a current production rod but heres' a link if you want to buy one. Good price on it too. FWIW, I know nothing about the retailer/website - good or bad.http://www.kandsoutdoors.net/viewitem.php?groupid=5&productid=907&cartid=907