I'm not into psytrance, but for my ebm-trance-etcetera basses I usually stick to saws, both classic and hypersaw, but you don't need 16 saws to have a killer sound...actually, I find the classic dual oscillators to be easier to tweak into something different...with hypersaw I always end up with a trance lead-bass, while with a classic dual saw I can find more inspiration.
If you wish, you can study the presets in the Virus (I'm sure there's something you like...there are more than 3k free presets around :P) and learn something about bass synthesis, but remember: don't be a clone, you need "your" sound, not others
good luck & good exploration