If you are looking for large lakers on the pen you will be very disappointed. Skilak has some decent fish, but they are pale creatures, as are those in Tustumena. Some can be found in Kenai Lake, but it is very hit and miss. There are some in Juneau Lake and Swan Lake up Resurrection Pass Trail, but hard to get to. I've heard there are a few in Trail Lake but can't speak from experience.
What lakers we have that are large are mostly found in Hidden, and they have been so overfished it is getting hard to catch them. Sad really, and I'm sure they will shut it down to C&R before long.
Your best bet is to go north to the Lake Louise area if you want larger fish, but even that lake is getting hammered. Alaska ain't what it used to be. Too few animals and too many people on a limited road system.
Now if you want some real laker action, fly out to Illiamna or Lake Clark or the Tikchik system. The fish tourists can't get those fish as easily.