Nothing in the 5- and 6-power range really stood out to me, so I decided to go top out the curve at 4 power and use Cauldron Cookbook as a card advantage engine, often being able to activate it and play whatever we draw in the same turn. Vara, Vengeance-Seeker and to some extent Ponysnatcher can help to offset any damage we may take from the Firebombs.
The ShiftstonedEternal Power Calculator is a deck-building tool that visualizes your odds of drawing enough Influence and Power based specifically on the cards found in your deck.