I built this out of a few cards I borrowed from a friend and what came in the core set I bought.

House Lannister

Plots

Fury of the Lion

Planning Ahead

Blockade

Wildfire Assault

Drunken Allegations

Summoning Season

Valar Morghulis

Characters -25

Ser Ilyn Payne x1

Lannisport Steward x2

Littlefinger x1 (Want at least 1 more of him)

Lannisport Weaponsmith x2

Lion Herald x3

Lannisport Councilor x3

Lurkers at Harrenhal x1

Shae x 2

Tyrion Lannister x1

Chella, Daughter of Cheyk x1

Enemy Informer x1 (Want 1 more of him)

Ser Jacelyn Bywater x1

Ser Jaime Lannister x1

Quyburn's Informers x1

Cersei's Attendant x1

Cersei Lannister x1

Joffrey Baratheon x1

Tywin Lannister x1

Attachments

Bodyguard x1

The Price of Nobility x3

Gilded Plate x2

Gutter Rat's Cunning x2

Milk of the Poppy x1

Locations

The Goldroad x3

Western Fiefdoms x3

Hall of Heroes x2

Golden Tooth Mines x2

Lannisport Brothel x1

Crossroads x1

Queen Cersei's Chambers x2

Shadowblack Lane x1

Lannisport x1

Sunset Sea x1

Events

You've Killed the Wrong Dwarf! x2

A Lannister Pays His Debts x2

The Lion's Will x2

I Never Bet Against My Family x1

Insidious Ways x1

I'm Your Writ Small x1

I'm fairly new myself and don't know the Lannister cards, but just based on what you have I would recommend dropping 5 locations for an extra 5 characters so your deck will be closer to the typically recommended ratios.

In removing those five locations, add in another Tywin and another Cersei, at least, if only for the duplicate.

I purchased the first 2 chapter packs for the Brotherhood Cycle, so I'm working and modifying from there. I do think you guys are on to something with removing 5 locations. I changed a bit yesterday and barely won during the 6th turn. So I think it's starting to come together.