Actually... With regards to EE
Ice only cost 1 EMC. As such, one stack of obsidian would translte into 64 STACKS of ice. Alternativly to make your system fully automatic
Energy Collector (any rating over a mark 1 is overkill) and an energy condenser. Wooden pipe and any kind of engine (I reccomend combustion as it moves whole stacks at a time) and pipe that ice into the reactor. Keep in mind, a reactor chamber won't accept stuff piped into it. It won't hook up so you can only have a 5 chamber design. aside from that, just let it sit and watch her go. Infinity ice until you run out of fuel. or if you use redstone engines, you'll never run out.