Some items that might not be in a kit would be a brew kettle, bottles, and a hydrometer. For extract, you can do partial boils, so you could use a 3 - 4 gallon kettle (I recomment 4 gallons). It can be aluminum to keep the cost down, but you'll need to build up the protective layer before brewing - I don't know the details because mine is stainless. Also, you can't use Oxiclean with aluminum. You need the hydrometer for making sure it is finished fermenting before bottling. I just got a bottling hydrometer that has a low SG range - much more accurate for FG readings.