If you don't mind driving a little more than 2 hours to Cooper's Landing in the Kenai, look up Fred and Stacy at http://www.mysticfishing.com/

I fished with them in 2005 and found their service, skills and knowledge of the Kenai to be first rate. Check out my trip report at the following link : http://www.fishingkaki.com/forum/viewtopic.php?t=7104

Stacy also runs a first rate cabin by the river.

Aug is a great time to be on the Kenai River. You'll likely encounter the Silver Salmon run and plenty of big Rainbows and Dollies. Have fun!