I believe there's a quest that walks you through creating magmatic orbs and then you put those into your smeltery. From there you can pour it out into a bucket and dump it right back into the smeltery tank. Cheap and easy, need lumite and slime balls if I remember right to make the orbs.
Magma creme is what you're thinking of.
If you dig around at a y=11, you'll find lava fairly often. If/when you get around to an ender quarry, a pump upgrade will provide you with more lava than you know what to do with.
There are ways to make lava in a magma crucible without the energy cost being a burden. The easiest way that is fairly early game is to power it with a stirling generator from ender io. With an octadic capacitor (a bit pricey, but not horrible if you have the pearls) a stirling generator produces over a million rf. Also, since you can't make a magma crucible before you go to the hell cube anyway, turn some cobble into netherrack, and it will cost a lot less rf, 120,000 I think. In all, one bucket of lava will generate 8. The easiest way to automate putting lava in a generator is with a casting table. No, seriously. place the magma crucible so that one of the outputs is against a casting table. Place a bucket in the table, and it will act as a bucket filler. Have the stirling generator also against the table, and configure it to automatically input and output. The whole system will fit in a 2x2 space.
If you really want to go nuts, 2 igneous extruders (one set to cobble, one to obsidian), an aqueous accumulator, a factory manager, and a chest will turn it into a fully self sustaining water/lava/cobble/obsidian/power factory.