Errm. No. That's not even nearly important, and it is in fact not even necessary. Also, I highly doubt his frame has 2 bolt mounts required to fit a Magura (which is the best/only choice really for trials).
If you seriously want to do it, start with the gearing as in, get it as minimal as possible and sort at a trials gear. After that, you'll want to fix up the brakes by investing in some decent vee pads and grinding your rim. You'll probably want to ask about for a better vee set up for trials as well (lever, cable etc). Then after that it's all personal preference. Wheels, bar, stem, headset, forks.