I'll guess Altruist uses the same process as I do: I often use Fruity to produce loops, but I make songs out of them in a dedicated sequencer (I use Cubase).
If you're new to making music on a computer, however (or even if you're pretty experienced), I would suggest just getting Fruity Loops for now, because it's a good all-in-one solution (I'd say it's the best). If you find the sequencer too limiting, then it might be worth looking into something like Nuendo or Cubase.
