We've fished the Kenai area the past 4-5 years and have had decent success, but it depends on what you want.
Reds on the Russian is a walk in and you can do it without guide. It is not so much a zipper lip, but if the sockeye are in the river, it is a great day. Make sure you get some Coho flies off of ebay as you cannot use corkies and the hooks have to be a certain way.
If you want the ability to keep a Kenai world class king, think after July 1. Before then there is a slot limit where you need to release (I believe) 44-55 inch kings. After July 1, you can keep them.
The Nugashak is supposed to be a kick in the pants if the runs are in. Not as big of fish as the Kenai, but supposedly "thousands" of them where you can catch 20+ in a day. We were supposed to fly in last year, but the run was behind, so never made it. We're going to try again next year.
I would recommend Halibut as well. Not the most fun of fishing as you pretty much just drop it to the bottom, wait for the fish to hook itself and then reel it up. Great table fare, though.
All of the above you would fly into Anchorage.
At the Sportsaman's show, however, I saw a booth for $1700 for self-guided fishing out of their lodge. They provide food, gear, etc. All of this for 1 week of fishing. That is a tough price to beat. No rental car required or nothing. With airfare to Petersburgh you're probably looking at about $2100. This is bay fishing and their website is
http://www.greenrockslodge.com I do not know anything about them other than I pulled a flyer.
Our guide (if you want the Kenai area) is Gary Kernan and he can set you up with whatever you want to fish for. Cabin, Kenai, Kasilof, Nugashak. He can talk to you about a whole trip. his website is:
http://www.alaskafishon.com. If you go with him, tell him you want Tony's cabins with Alaska Lodging & Adventures. Free vaccuum pack, only you pay for the bags. And, he is a hell of a nice guy.
We usually try to mix it up. We never have really hit the silvers hard, but hear there is a hell of a silver run. Sockeye on the Russian is a good time and you are likely to see some big brown bears.
Any questions, feel free to PM me as we know of some good walk-in places, as well.