I had a browse through BG Wiki and picked up what Fast Cast gear I could find:

RUN equipable Fast Cast gear

30% Fast Cast, plus Siegel Sash for -38% total casting time for enhancing magic. Still leaves Stoneskin over 6 seconds to cast though.

Not to mention that Athos Chapeau aside, the rest of the gear offers nothing else useful for RUN. Athos Chapeau has MAB +4% which you could use in a lunge macro. But for your 38% it's 9 inv slots, and not everyone can afford that. Especially if you want to pimp a lunge set too.